Travel 101: Our Favorite Hacks, Hints and How-Tos

Consider packing allergy-friendly snacks for your trips. Some of the reliable brands without peanuts, tree nuts, gluten and dairy are MadeGood and Enjoy Life. (Make sure to double-check all ingredient labels anyway to be safe.) These portable products include snack chips and granola bars. For travel within the United States you can also store fresh fruit in resealable bags with reusable mini-ice packs, which are permitted in carry-on luggage, but the ice packs must be placed with other liquids when you’re passing through security.

If you travel with an epinephrine injector, insert a tracker like an Apple AirTag or Tile in its case and place it in your carry-on. Then, set an alert to notify you if you forget it at home or misplace it during your travels, so you will never be without it. The Transportation Security Administration limits passengers to two injectors, which should be kept in the original box with a visible prescription label.

The Food and Drug Administration also suggests packing cleansing wipes. Unlike hand sanitizer, disinfectant wipes can remove up to 99 percent of allergens, including peanut residue, from surfaces. This can help protect you from cross-contamination. Be sure to wash your hands afterward to avoid direct contact.

Tell your hotel what you need

The Americans With Disabilities Act helps to protect those with food allergies by giving them the right to ask for necessary changes in hotel policies or conditions that place them at a disadvantage. However, hotels and rental properties can’t always guarantee allergy-conscious accommodations. When booking, prioritize establishments rated highly by other travelers with dietary sensitivities in online tools like the Spokin app and blog. The service allows you to search allergy-specific reviews of hotels and restaurants. Walt Disney Resorts, Hilton, Marriott, Fairmont, Kimpton and the Four Seasons are a few highly rated global hotel chains. Additionally, all Kimpton Hotels around the world offer a Forgot It? We’ve Got It program, in which they stock nonallergenic toiletries and snacks.

Most hotel booking apps allow you to limit your search to rooms with a kitchen, should you prefer to have the control that comes with preparing your own meals. If you can’t book a room with a kitchen, you may be able to ask the front desk for a microwave and a mini-fridge to store and reheat your own meals. When you book, personalize your profile with details of your dietary sensitivity and confirm with managers upon arrival. Be sure to ask them to also make their staff aware.

Airbnb and Vrbo properties typically come with a full kitchen, but remember to wash cookware and service items with hot soapy water before use to reduce the risk of contamination.

Fly allergy-friendly skies

The Air Carrier Access Act, like the A.D.A., protects airline passengers with dietary sensitivities by permitting early boarding for travelers to clean the seats and other surfaces. Although many airlines do not currently serve peanuts, a common allergen, there is no guarantee that onboard snacks do not contain traces of peanuts, which could set off a reaction. Some flights have designated areas called buffer zones, where peanut products are not served or eaten by passengers. Contact the airline before booking to learn about the specifics of your flight.

At the airport, Spokin can help locate nearby suitable meal options in 80 countries. You can filter by your specific dietary restriction and view thousands of user reviews for each establishment. The FindMeGlutenFree app searches worldwide airports for celiac-friendly options.

Talk to the chef

It seems simple, but filtering a Google Maps search with the keywords “specialty markets” can reveal a world of allergy-friendly options as well as helpful reviews. Organic markets or health stores are often good alternatives for people with food intolerances.

If you’re planning to eat out, platforms like OpenTable allow you to make direct requests for accommodations in 80 countries. The AllergyEats app lets you search for restaurants with dietary restrictions by state, but it is available only in the United States.

For international destinations, consider carrying a downloadable chef card from the nonprofit group Food Allergy Research & Education to convey, in any of the 10 languages besides English offered on its website, what foods a restaurant must avoid serving you. The iTranslate app can translate from a photograph of a menu or a sign to help you convey your needs to the restaurant staff.

For U.S. getaways, when possible, choose off-peak hours to dine — typically between 2 and 4 p.m., versus during the lunch or dinner rush. At those times, the chef is more likely to be able to speak with you about special meal requests. Also, without orders piling up, the kitchen staff can lower the risk of cross-contamination by taking more time to prepare your meal carefully.

Lisa McCarty is a writer and a women’s health advocate. You can follow her on Instagram and Twitter.

For more travel advice, visit our collection of Travel 101 tips and hacks.

The “routine” processing time to replace a passport takes six to eight weeks and costs $165; choose the “expedited” service, for an additional $60, to receive your passport in two to three weeks.

You might even get yours “faster than advertised,” said Matt Pierce, a managing director of passport services for the State Department, noting that the pandemic-era backlog was cleared up as of December.

Avoid delays by carefully following instructions, and consider spending an additional $19.53 for faster shipping.

When time is tighter

If your trip is less than three weeks away, you’ll need to take the extra step of going through one of 26 passport processing offices across the United States. If you’re doing it without an outside expediter, you must make an appointment online or over the phone, up to 14 days in advance of your trip.

There are no more walk-ins, an option before the pandemic, but the State Department has increased capacity to eliminate the need for them, Mr. Pierce said, and the offices give special priority to documented “life-or-death emergencies” of immediate family members. You’ll need to bring all of your documents, and proof you are traveling soon — like a plane or cruise reservation.

Things can get dicey if you need an appointment in the next day or two. In such cases you can call for an appointment, or contact your local member of Congress.

Laurie Lee, the chief executive of Chicago-based Swift Passport and Visa Services, an expediter, has seen cases where clients on the verge of missing a wedding or another once-in-a-lifetime event spend hours refreshing the site to find a last-minute appointment, and even end up booking flights across the country if they can find an opening. That, of course, costs both time and money.

At the passport office, the process will be similar, except that you’ll likely be able to pick up your passport later in the day. In most cases, said Mr. Pierce, you won’t have to return the next day, but it can happen. (You can also have your passport mailed to you, if you have time.)

Using an expediter

If you have at least three business days and are willing to spend hundreds of dollars for help, consider Swift or one of the other 200-plus agencies registered with the State Department as couriers, or expediters.

Expediters are especially helpful for people who live far from the nearest passport office and cannot or do not want to drive or fly there. But they can also benefit anyone having trouble getting a timely appointment, because they have reserved slots that allow them to bring a client application directly to certain passport offices. Swift, for example, can bring 10 applications a day to the Boston office, and five to the Chicago one. Depending on urgency, Swift’s assistance costs between $155 and $599.

To work with an expediter, you will still need to go to your local passport acceptance facility, like a post office, where workers verify and seal your documents in an envelope, which you then send (or hand-deliver) to the expediter. They’ll take care of the rest, and get your new passport back to you.

What can go wrong

If you’re traveling to a passport agency, leave plenty of time to get there. Screwing up something on the form can also lead to delays that cost you your trip.

“Common errors include signing in the wrong place, not putting the date on their application, having an incorrectly sized passport photo or not being framed correctly in the photo,” said Steve Diehl, chief corporate development officer of CIBTvisas, a large expediter.

Once you get it

When your passport arrives, make digital and paper copies. Change your number on trusted traveler programs like Global Entry, and remember that if your old passport had a visa in it for the country you’re headed to, you’ll also need to rush a replacement of that.

If you do find your old passport later, keep it as a souvenir: It is no longer valid.

If you lose it while abroad

First of all, try not to. Unless you are traveling in a country that strictly requires you to have your passport on your person at all times, stow it in a hotel safe and carry around a photocopy, plus your drivers license.

But if you do lose the passport or have it stolen, report it online to protect yourself from identity theft and then contact the nearest U.S. embassy or consulate for an emergency appointment. You’ll need that paper or a digital copy of your passport, plus similar documents to what you would need for a replacement in the United States. You may receive either an actual replacement passport or an emergency version, usually good for one year.

In a real emergency, you can try a last ditch maneuver: Ask the airline to contact U.S. Customs and Border Patrol to seek permission for you to enter the country without a passport.

Preventative measures

Several expediters advised that many of their clients misplaced their passports during recent moves, so when you pack up your home, be sure to remember where your passport is packed.

Oh, and before you give up on that lost passport, check your home copier or scanner. “I can’t tell you how often people find it in their copy machine,” said Ms. Lee.

Familiar brands may be franchisees

Car rental brands familiar to Americans operate throughout the world; those include Alamo, Avis, Hertz, National, Sixt and others. You can reserve a vehicle through a company’s U.S. website or through a rental aggregator such as Autoeurope.com, to compare rates.

The overseas branches of U.S. companies may not always be owned by the parent company. The discussion boards on websites like Tripadvisor abound with commenters calling out franchise operations of major chains for not providing the service they expect from a U.S. operation.

Franchise or not, disputes with a foreign branch should always be directed to the U.S. customer service operation, according to Hertz and Autoeurope.

Check minimum (and maximum) age requirements

The minimum age to rent a car varies by country and company, and it’s indicated on each rental agency’s website. Most countries charge a “young driver” surcharge for renters under 25. Some countries, such as France and Germany, allow (but do not require) companies to rent to 18-year-olds, but 21 is the typical minimum rental age for most.

At the other end of the spectrum, Hertz won’t rent a vehicle in Northern Ireland to anyone older than 79; those from 75 to 79 must have a doctor’s letter stating that they are in good health, as well as a letter from their insurance company proving that they haven’t had an accident within the past five years.

Cut costs with a stick shift

Cars with manual transmissions are still popular in many European countries, so if you’re comfortable driving one, select that option. Renting a car with an automatic transmission can typically cost an additional 30 percent or more.

Check your credit card’s rental insurance coverage

Many U.S.-issued credit cards cover damage to your international rental car if you’re in an accident, as long as you charge the entire rental fee to the card. Some issuers also require that the same card be used to make the reservation for the insurance to be valid. That collision coverage is primary, unlike in the United States, where your personal vehicle insurance would cover the costs while your rental insurance would pay for any deductible amount. Even if your credit card covers damage to your rental vehicle, you will be responsible for the cost of damage to any other vehicle if the accident is deemed to be your fault.

Be warned that standard rental insurance for American Express cardholders is not available in Australia, Italy and New Zealand, and other cards may have different restrictions.

Familiarize yourself with local driving and parking laws

Before you go, learn each country’s rules, including the meaning of various road signs and markings. For instance, simply because you see other vehicles parked with their wheels on the sidewalk — common in European cities with narrow streets — that does not mean that it’s legal to do so.

Autoeurope.com has driving tips for dozens of countries, not all in Europe, and Britain’s Automobile Association lists road rules for six European countries. Don’t forget that many places besides Britain drive on the left (including Japan, Australia, New Zealand, South Africa and numerous Caribbean islands). And if you get a ticket, don’t ignore it. The rental agency will eventually collect from you, along with an administrative fee.

Seatbelt laws are often strictly enforced, with a separate fine — sometimes issued on the spot — for each occupant not wearing one.

Finally, many European cities restrict driving in central or historic areas to residents only or those driving low-emission vehicles. Entering these limited-traffic zone areas can incur heavy fines, plus an added fee from your rental company. Watch for signs and gates (commonly marked “ZTL” in Italy).

Know your fuels

Diesel engines are very common in other countries; putting diesel in a gas engine or vice versa can cause serious — and costly — damage.

While fuel pumps are color-coded to indicate what they dispense, those colors vary by country and region. Fuel requirements are listed on a sticker on the inside of the filler door.

In the United States, black indicates gasoline while green designates diesel. In Iceland and other European countries, it’s the opposite: green for gasoline and black for diesel.

Pack your carry-on smartly and strategize early

You’ll most likely be checking your luggage, so your carry-on bag will need to be well equipped. As well as any items you’re going to use for entertainment, think ahead to what will help you feel the most comfortable. Packing a change of clothes (if there is a stopover, you may be able to find a shower in the airport) as well as a toothbrush and toothpaste will go a long way to helping you feel fresher during your journey. Make sure you’re wearing comfortable clothing and a pair of compression socks to combat swollen feet from so many hours with little physical activity.

“Wear a hoodie,” recommends Nikki Greenberg, 40, a futurist and innovation strategist from Sydney who frequently travels internationally for work. “It is cozy, warm, covers the ears (less noise) and eyes (less light for sleep), and creates a private cocoon environment.”

Find a way to sleep as much as possible

Do anything and everything you can to make sure you spend a large chunk of the time onboard asleep. Some travelers consider sleeping pills or melatonin supplements as must-haves, while eye shades and noise-canceling headphones can reduce cabin lighting and help to dull the roar of the plane. A travel pillow like the Trtl Pillow, which supports your neck, can help when trying to sleep in the upright position.

Mapping out your sleep schedule ahead of time can also be useful, depending on when your flight or flights are departing. Vanessa Quincey, 33, an advertising director from Melbourne, Australia, who has lived in New York for the past decade, stays awake for the shorter leg of her journey — New York to Los Angeles — to ensure she’s extra tired for the long second leg to Melbourne.

“Purchase a ‘Do Not Disturb’ eye mask if you plan on sleeping through meal service,” she said. “The mask will block out the overhead lights, and the ‘do not disturb’ will let the cabin crew know not to wake you.”

Save up entertainment

Plan how you will fill the rest of the time onboard: A 10-episode narrative arc of a TV series will stretch out a lot longer than one movie. You can look ahead on the airline’s website to see what in-flight entertainment will be available on your flight. Be sure to download TV shows, movies, podcasts and music onto your devices before you get to the airport and have to rely on spotty Wi-Fi. Bring a good book you’ve been meaning to read. Have some offline games you can play on your phone or iPad. And don’t forget a backup portable charger.

Patrick Quade, a 52-year-old tech founder from New South Wales in Australia, has done the trip between the United States and Australia more than two dozen times. He recommends setting a goal that takes longer than 20 hours: “Learn Adobe Premiere well enough to make a three-minute short with edits and sound track.”

Never stop hydrating

The air onboard is extremely dry. Pack a decent moisturizer, lip balm, lubricating eye drops and a small nasal spray. Try to avoid alcohol and drink as much water as you can throughout the flight: Bringing your own empty water bottle to fill up at the airport after customs can help with this goal. Powdered vitamins or electrolytes can be added to your water to maximize hydration.

Move when you can

Many people prefer an aisle seat so they are able to get up frequently without disturbing their seat neighbor. Ahead of booking, research the layout and model of planes on websites like SeatGuru to find the most legroom. Do some stretches while you’re waiting in line for the bathroom and walk a few laps of the terminal during a layover to get your blood moving.

Think ahead to your final destination

Without a doubt, the most important thing is to never, ever take a nap if you land during the day, as tempting as it is after a grueling flight. “This is really tough flying to Australia because you usually land early in the morning,” says Nathan Weinrich, who has been traveling home to Australia from New Jersey for eight years. “But it makes a huge difference to how quickly you adjust to the new time zone.”

Bring a carry-on

After you check your bag at the terminal, it may take several hours before it’s delivered to your stateroom. “Be sure to pack a carry-on with all of the essentials you might need during that window of time,” said Colleen McDaniel, editor in chief of the cruise news site Cruise Critic, who suggested including “medication, sunscreen, a bathing suit, a phone charger and other essentials that you’ll need as soon as you board.”

Sign up for activities in advance

Popular onboard restaurants, shore excursions and spa treatments can fill up quickly so book ahead. Many companies will let you book in advance through their website or app, but if not, head to excursion and activity desks soon after you’ve boarded.

“The theater productions are incredible and produced at a very high quality,” said Chris Thompson, an avid cruiser of 35 years based in London. “You can usually reserve a seat in advance for free, but if it’s booked up, try showing up 15 minutes before the start of the show when seats often become available.” Mr. Thompson also suggests going to a specialty restaurant on the first night when there is likely to be more availability. “Most people eat in the main dining room while they settle in, so chances are you’ll find a nice table at one of the special restaurants,” he said.

Bring your own drinks

Beverages are expensive on cruises and can add up. Many lines offer all-inclusive food-and-drink packages for a flat fee, which can save money, particularly for those who enjoy alcohol, but it’s also worth bringing your own. Be sure to check your ship’s policy as the rules vary from line to line, and passengers may be limited to a quota of beverages they can bring onboard. Many cruise lines have apps where you can check on your daily charges and make sure they are accurate. Taxes and service charges are usually added automatically.

Switch your phone to airplane mode

During your cruise, you will likely be crossing through several international telecom networks and could rack up significant roaming charges as your phone automatically downloads data. It’s best to keep your phone in flight mode and connect to the ship’s Wi-Fi if it’s included or if you decide to purchase a package, which usually ranges from $15 to $40 per day.

Catch a deal during a port stop

On longer cruises with several stops, it can be worthwhile to stay on board and make the most of the ship’s offerings during an excursion day. Many lines will offer deals on spa treatments, restaurants and activities during port calls and it’s a good opportunity to use the ship’s facilities when they are less crowded.

Know that your itinerary may change

Itinerary changes are common on cruise ships and could occur at the last minute. Factors like weather, wars and civil unrest can disrupt what ports you leave from or stop at, and cruise lines will either substitute a stop or spend longer at the next scheduled destination. Refund and cancellation policies vary between cruise lines, so read the fine print. Even if an itinerary change doesn’t result in a refund, some companies may offer cruise credits as a courtesy.

To have your trip fully covered, consider taking out travel insurance. “A cruise is an investment of money and time and should be protected,” said Stewart Chiron, a cruise industry analyst and chief executive of the news site cruiseguy.com. “Besides providing protection for cancellation, policies also cover for interruption, medical, travel delays, property loss and are worth serious consideration,” he added. “If itinerary is a major determinant, consider a policy covering ‘cancel for any reason’ in case of major changes.”

Don’t be shy

The idea of being in the middle of the ocean with thousands of strangers can feel intimidating, but it’s a great opportunity to meet new people, particularly experienced cruisers who can offer tips in real-time.

Cruise Critic has Roll Calls for guests on a particular sailing to join and chat with one another in advance. Passengers have also used Roll Calls to form groups to plan independently booked shore excursions, which can be cost-effective.

“But be aware,” said Ms. McDaniel of Cruise Critic, “If you’ve booked an independent shore excursion that runs late, the cruise line does reserve the right to leave without you if you’re unable to return to the ship in time.” She notes that the ship will wait if you’ve booked an excursion through the line.

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If you’re flying and choosing an off-airport rental location at your destination, factor in the cost and convenience of transportation to the agency. Most have more limited hours than airport-based outlets, which could be important if your flight is delayed.

Don’t prepay

Many agencies offer discounts for prepayment. But prepaid contracts often incur fees if you cancel.

Most unpaid reservations are flexible, allowing you to cancel anytime with no penalty. Experts advise reserving early and then using the time before your trip to check prices. If they go down, you can cancel and rebook at the lower rate. Many agencies, including Budget and Dollar, offer best rate guarantees, meaning if you find a better rate on their cars elsewhere and they can verify the claim, they will rent you the car for 10 percent below that price.

The website AutoSlash will track your reservation at no cost and alert you to any price drop.

Maximize your memberships

Use memberships at the retailer Costco or the organizations AAA or AARP to get a discount at specific companies. Payoffs vary. If you’re strictly joining Costco to rent cars, it may take a few rentals a year to recoup the $60 membership fee.

If you join loyalty programs at Avis, Hertz or other major rental companies, which are usually free, you are entitled to express pickups, which means you can skip the line at the counter and go directly to your vehicle.

Consider alternative companies

Turo and Getaround act like Airbnbs for rental cars: Owners offer their vehicles to rent through company websites or apps. Turo, available in 11,000 cities in the United States, Britain, Canada, France and Australia, requires renters to work out where and when to pick up cars from their renters, though some owners will bring the car to you.

Available in more than a dozen cities in the United States, the app- and internet-based rental company Kyte, which has no brick-and-mortar locations, will drop off and pick up its cars, which are competitively priced, wherever you specify, at no extra charge. The contactless and app-based UFO Drive rents E.V.s in more than 20 cities in the United States and Europe.

At the counter, understand upgrade policies …

At traditional agencies, when the car you’ve reserved is not available when you arrive, it’s a common practice to give you the next-best available car at no extra charge. This may not always be made clear, and agencies have been known to ask if you want to upgrade for a fee. Before accepting, request your original class of car. If it is not available, you are entitled to a free upgrade.

Watch out for “manager’s specials,” which tend to be bargain leftovers. As agencies transition to electric cars, renters have ended up with surprise E.V.s that they didn’t necessarily want, according to Mike Taylor, the managing director of travel, hospitality and retail at the market research company J.D. Power.

… and know your insurance coverage

If you already have auto insurance, in most cases that coverage extends to a rental. Many credit cards also provide coverage against theft and damage as long as you use that card for payment. Check on both before buying additional coverage at the agency.

“Credit card insurance is only collision, not liability,” Mr. Weinberg said, noting liability insurance will add roughly $20 a day.

If you do not have insurance and are relying on a credit card’s coverage, pay attention to exclusions of certain kinds of car and peer-to-peer rental agencies like Turo.

“You want to avoid duplication of coverage, but you don’t want to go in thinking you’re fully covered when you’re not,” said Chuck Nardozza, the managing director of sales at AAA Northeast.

Most personal auto insurance will not apply to driving abroad, with some exceptions for Canada and Mexico.

Before driving off, document the vehicle’s condition

Look for damage, including dings and scrapes and upholstery tears. Take photos or a video to establish the vehicle’s condition at pickup. If there is damage, ask the company to document it in your paperwork.

Take photos again when you drop off the vehicle. Even if an employee reviews the car and gives you a receipt, you’ll have a record of its condition should a deeper review find any damage.

Before returning the car, buy gas

Fuel options include returning the car with a full tank or having the company refill it at what may look like attractive per-gallon rates. However, in the second scenario, you must buy a full tank.

“If you use three-quarters of a tank, you’re giving the rental car company a quarter tank of free gas,” Mr. Weinberg said.

When you return the vehicle, take a picture of the gauge showing a full tank. Companies have been known to tack on extra gas charges, and photographic proof usually wipes those charges away.

Return the car on time

A rental car day is usually 24 hours from the time you leave the lot. Anything later might incur another full day’s charge.

Even if you reserved a car from noon on pickup day to noon on drop-off day, if you arrive early and take the car at 11:30 a.m., you’ll be expected to return it by 11:30 a.m. on the due date. “They might give you a little leeway, but that window tends to be short, like 60 minutes or less,” Mr. Nardozza said.

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Credit cards are often safer than cash because fraudulent charges can be disputed. (But given high interest rates, use credit cards only if you regularly pay off the balance in full.)

If you are planning on paying primarily with credit, bring a second card as a backup in case the first is lost, stolen or declined.

Ask to be charged in the local currency

If you are offered the choice to be charged in U.S. dollars or the local currency, always go with the local option.

“People feel like they’re playing with Monopoly money so they will say yes to the U.S. price because they know what it is, but you should let the credit card company do the conversion,” said Sally French, a travel expert with NerdWallet.

Merchants offering to charge in the local currency or U.S. dollars are engaging in “dynamic currency conversion” or setting their own exchange rate, which is typically worse than the going bank rate. Mr. Ewen of the Points Guy has seen a markup of 3 to 10 percent for paying in dollars.

“The reason you get a favorable exchange rate with a credit card is the issuer is operating at much more scale and they’re able to do a large volume of transactions,” said Greg McBride, the chief financial analyst at Bankrate, a personal finance site.

Don’t exchange money at the airport

Though you may need cash upon arrival in a foreign country to pay for a cab or tip a bellhop, don’t get it at an airport.

“In general, the worst place to exchange currency is, in fact, the airport,” Ms. French said.

She advises ordering a small amount of foreign currency from your bank before you fly. This method may not deliver the best exchange rate, but it usually beats the airport currency desk, Ms. French said.

Other experts recommend holding out for foreign cash until you arrive and can use a local A.T.M., where you will most likely get a better exchange rate.

As with credit cards, if you’re given the option, always choose to have a withdrawal debited in local currencies. Some A.T.M.s will engage in dynamic currency conversion and dispense local currency but debit your account in a U.S. dollar amount; don’t fall for it.

Also, larger hotels will often convert small amounts of money for their guests.

Beware of A.T.M. fees

Expect to pay $2 to $6 to use a machine that is out of your bank’s network, plus an additional foreign transaction fee, usually 1 to 3 percent, according to NerdWallet. To avoid excessive fees, limit the number of times you use an A.T.M. by withdrawing larger amounts.

Check with your bank to determine whether it has a reciprocal relationship with a foreign bank that allows you to use its A.T.M.s without incurring out-of-network charges. For example, Bank of America has partnerships with a number of banks in Canada, Europe and the Caribbean, though it generally charges 3 percent of the amount withdrawn as a foreign exchange fee.

Citibank will waive out-of-network A.T.M. fees up to a certain number of monthly transactions, depending on the type of account. Charles Schwab Bank offers a checking account with unlimited A.T.M. fee rebates worldwide. Capital One offers a checking account with fee-free access to more than 70,000 A.T.M.s globally.

Use mobile payment for transit

Depending on where you’re going, check whether local transit systems accept mobile payments such as Apple Pay or Google Pay, which allow users to store a credit card in a cellphone app for contactless transactions. Transport for London, for example, allows mobile payments and will cap any charges once you’ve reached the price for a day pass.

The systems in Stockholm and Toronto also allow mobile transactions.

Don’t return home with coins

In countries like Canada and Australia, local currency commonly comes in high-denomination coins valued at $1 or more. When paying with cash, it’s easy to find your pockets weighted down with coins. Try to spend or donate them abroad, as it is harder to exchange coins for U.S. dollars once you are back stateside. Bank of America, for example, does not accept coins for conversion.

Layer your picture with details

Successful landscape shots draw the eye across the whole frame, and for that you need to search for points of interest in the foreground, middle ground and distance. Find a vantage point that lets you see the different layers of a scene. Test different compositions by turning your cellphone both vertically and horizontally, and, if you have a choice of lenses, decide if the scene is best framed tightly or wide. Another way to enrich the landscape is to spot a person or an object and place them carefully in the frame as a focal point. It could be someone walking alone along a beach, or a tree on a hillside, or a horse in a field or a bicycle leaning against a wall. But look for something that catches the eye, giving scale and contrast to the scene.

For portraits, find the right backdrop

Look for a clean background — a natural canvas with relatively solid coloring or shape, like a wall, open sky or foliage. If that’s not possible, move around the subject to find a backdrop that is less cluttered. Also, check that there are no upright objects, such as streetlamps or thin trees directly behind people’s heads, or other unwanted items in the background that will distract from the subject.

Work the frame

It’s often helpful to have a portrait shopping list: headshot, half-body and full body frames (make sure not to cut off people’s feet), as well as horizontal and vertical ones. Having these frames in mind will help you choose the best shot. Many of the latest Apple and Android phones offer a choice of inbuilt lenses with different focal lengths, which help you do this quickly. You can also use the portrait mode on your cellphone’s camera, which shortens the depth of field, blurring the background and giving a portrait style that is similar to what you would get when using wide-open apertures on longer camera lenses.

Edit your photographs more than once

Choosing the best pictures is just as important as taking them. If you have been making a separate album of your favorites, you already have a base from which to start. Nonetheless, take your time and go through all the photographs you have taken, scrolling through the images at least twice. If possible, leave a day between doing so. The eye can get overwhelmed when looking at a large number of images, and it’s easy to overlook a good picture.

Go easy on post-production

Phone cameras, just like regular cameras, are not always able to read the light correctly. Often one needs to adjust a photograph’s exposure, shadows or color temperature. A lot of this can be easily done with a phone’s inbuilt software — though there are also plenty of specialist applications like Snapseed or Adobe Photoshop Express. What you can or should do is a personal decision. But, in general, spend as little time as possible working on a picture, and concentrate on balancing tone and lighting across your selection of images so they feel cohesive in style.

Have a hungry eye

Eve Arnold, the wonderful Magnum photographer, used to recount a story about walking with Henri Cartier-Bresson from the Magnum office in Paris to have lunch at his apartment on the Rue de Rivoli. During the 15-minute stroll home, as he kept telling her that he was no longer interested in photography, only drawing, he took three rolls of film on his Leica. The great photographers have an insatiable eye for images, and a cellphone allows one to be ready for everything. But it’s also necessary to understand the moment clearly. Everyone wants their memories of a journey to be captured so they can reminisce later. But it’s also important to see the world without feeling the obligation to take a photograph. Sometimes the eye just needs the pleasure of looking.

It can help to know what airlines your carrier partners with, in case you need to be rebooked on another airline. In addition to partnerships like code shares, when an airline operates a flight on behalf of another, or alliances, most airlines also have relationships known as interline agreements that allow them to transfer passengers to flights on other carriers.

This information isn’t always readily available online; experts suggest calling an airline’s customer service for more guidance.

Be aware that if you have a ticket with a low-cost airline, like Frontier Airlines, Southwest Airlines or Spirit Airlines, you are most likely out of luck: They generally do not rebook on any other carrier.

Go deeper than the dashboard

The Transportation Department’s airline cancellation and delay dashboard is a helpful resource that spells out what 10 of the larger domestic airlines offer passengers. But this dashboard is not your only tool. Customer-service plans for specific airlines (located on their websites, and with links from the D.O.T. dashboard) have further detail about passenger entitlements.

For example, if your United Airlines flight is canceled because of reasons within the carrier’s control, such as understaffing, and you are rerouted to a flight that departs the next day, you are entitled to a voucher for food, a nearby partner hotel and transportation. If a room is not available at the airline’s hotel, and you must find another accommodation, United will reimburse you for “reasonable hotel costs.” There’s nothing on the United customer-service site indicating that food receipts or taxi receipts will be reimbursed.

If a delay or cancellation is the airline’s fault, most major carriers can also rebook you on another airline. A few have this ability regardless of what led to the disruption.

In most instances, American Airlines will rebook you on another airline if there are no American flights until the next day. Delta Air Lines also commits to organizing flights on alternative airlines if necessary, though it is not clear under what circumstances it will do this.

Strategize your ask

In the United States, if your flight is canceled, for whatever reason, all airlines must either rebook you on another flight or give you a prompt refund, even if you have a nonrefundable ticket, according to the Transportation Department.

When a delay or cancellation is caused by the airline, passengers — in most cases — are entitled to a handful of services after wait times have exceeded three hours. Major carriers will provide meals or meal vouchers. And if travelers are forced to stay overnight, most airlines will cover the costs of a hotel stay and associated transport.

But getting what you’re entitled to can be a challenge when hundreds of passengers are lined up and waits for a customer service rep on the phone can stretch to hours. That’s where being strategic can make a difference.

Mary Cropper, a travel specialist at Audley Travel, advised against asking for help at the gate, where many other passengers will be, too. Instead, seek out an airline’s service desk. Airport lounges, some of which are accessible by day pass, may also be a swifter avenue to assistance, she said.

When you do reach the customer service rep, be prepared with the specific request for the outcome you want, whether it’s being rebooked on a certain flight or a flight on a partner airline, or departing from a different airport from the one you might be stranded in. Don’t just ask what your options are.

“If an alternate flight arrangement does not get you where you need to be or when you need to be there, ask for something better,” said James Ferrara, the founder of InteleTravel, a global travel adviser network. And mention if you’re a frequent flier or have an inflexible commitment like a wedding or a work conference, he added.

Just do it

Experts said passengers can also take matters into their own hands, whether that’s booking a hotel or a new flight, and submitting receipts later for reimbursement with an airline’s customer relations team. However, there is some risk that an airline won’t foot the bill, said Bobby Laurie, a travel expert and former flight attendant.

“You also have to be 100 percent sure you are in the right and are owed the reimbursement,” he said. “Armed with information, you make the best advocate for yourself. But you really, really, have to read the fine print.”

Understand that rights may differ with international flights

In the European Union, flight cancellations or long delays may give passengers the right to either a refund or a replacement flight. There may also be compensation of up to 600 euros, around $660, based on factors such as how long you waited, how much notice you were given about a schedule change, the flight’s distance, and the cause of the delay or cancellation.

The rule covers all passengers, regardless of nationality, and outbound flights from and within the European Union, including on U.S. carriers. On flights into E.U. countries, it applies only to E.U. carriers.

AirHelp, a Berlin-based flight compensation company, has a comprehensive guide outlining passenger rights in many countries.

Know you might be out of luck if the weather turns

Any compensation or help offered by the airlines hinges on whether the reason for the cancellation lies within a carrier’s control, such as staffing or maintenance issues. Air traffic control woes and the weather are not. Weather is the leading cause of delays this year to date, and “creeping delays” are the bane of every air traveler.

It may feel unfair, but “if your flight is canceled because of a thunderstorm,” said Scott Keyes, the founder of Going.com, a website that sends alerts for travel deals, “don’t expect the airline to cover your meals or accommodations.”

If you choose a card that’s not co-branded, you can sometimes transfer your points to your preferred airline’s loyalty program. For cards that don’t have partnerships with certain airlines, you can often use code-sharing as a workaround. For example, Capital One does not allow you to transfer your points directly to Delta SkyMiles. To book a seat on a Delta flight, transfer your points to Aeromexico — which Capital One does have a partnership with — then use those points to book a code-share seat on Delta through the SkyTeam alliance.

Stretch points into pennies

Redemption values can change depending on how you use your points, said Gary Leff, of the travel site View From the Wing. His advice: Explore the variety of ways you can redeem them and aim to get at least one penny per point. Citi ThankYou points are usually worth a penny when buying gift cards from a variety of retailers. American Express cardholders will get 1 cent per point when they’re using their Membership Rewards balance to purchase an airline ticket or a hotel room on the Amex website — and some also earn five points per dollar spent. For example, a $500 room booking will cost 50,000 points, but earn 2,500 points, worth $25, for buying it through the website.

Those same Amex points are worth only about 0.7 cents if used to make a purchase on Amazon and 0.6 cents if used to pay for eligible purchases on your monthly statement. Credit card websites typically have a section detailing redemption values.

Sometimes, points can exceed 1 cent in value if you transfer them to an airline loyalty program to buy a ticket, Mr. Leff said. And keep an eye on travel websites, social media and your email inbox for temporary transfer bonus offers, which can give you an additional bump of up to 30 percent on points you are moving to a specific airline or hotel partner.

Save big expenses for new cards

Tempted by a hefty sign-up bonus? Wait until you’re planning a big vacation, doing a home renovation, or paying college tuition or another large expense, advises Kylie Queisser, who offers travel advice on TikTok. Then use that big expense to meet the minimum spending requirement for the bonus. The Capital One Venture X Visa card ($395) offers 75,000 miles after spending $4,000 in three months. The Citi AAdvantage Executive World Elite Mastercard ($595) was recently offering 100,000 points for spending $10,000 in three months.

Bonus amounts like those can be significant: 75,000 Capital One points can be redeemed for $750 in travel spending; 100,000 American Airlines miles could buy several cross-country plane tickets.

Play to each card’s strengths

If you don’t mind a little juggling, tailoring individual cards to specific purchases can maximize benefits. For example, pair a Chase Sapphire Reserve card ($550), which earns three points per dollar on travel and dining expenses, with a no-annual-fee Chase Freedom Unlimited card, which earns one and a half points per dollar, for everything else, Mr. Leff suggested. “There are similar ways to pair American Express cards and Citibank cards,” he said.

So how do you keep track of which one does what? Easy, Mr. Leff said: He puts little stickers indicating restaurants, gas, groceries or other categories on each of his family members’ credit cards.

Check your hotel room before you settle in, even if the room is spotless. The warmth, blood and carbon dioxide of humans are far more important to bedbugs than an unsanitary environment, according to the Environmental Protection Agency’s bedbug myth website. But, the website adds, clutter can help them hide.

When you first enter the room, immediately put your luggage in the bathroom, then do your bedbug inspection, advises Jody Gangloff-Kaufmann, a senior extension associate at Cornell University who focuses on pest management and has a doctorate in entomology.

Adult bedbugs are wingless and have six legs and a flat, oval body. They’re about the size of Lincoln’s head on a penny, according to the Centers for Disease Control and Prevention. The eggs are pearl white and about the size of a pinhead, the E.P.A. website says.

Thoroughly check the bedding, box spring, bed skirt, side tables and even the alarm clock, anywhere the bugs can hide.

“The first thing you might notice is the fecal stains that they leave behind, which is kind of like magic marker dots in fabric,” Dr. Gangloff-Kaufmann said.

Also check the headboard; some can be popped off the wall. If there is powder behind the headboard, Dr. Gangloff-Kaufmann said, that may a sign that the room has been treated for bedbugs in the past.

Pack a small LED flashlight you can use as you do your inspection. It will help illuminate any eggs or shells discarded during molting. Finally, check the rest of the furniture and any nooks or crevices — think baseboards, moldings and floors — around the room. A sweet, musty smell may also indicate the presence of bedbugs.

Commercial bedbug tests such as the swab-based TruDetx, which promises “reliable detection in just five minutes” may work, but do not have enough scientific studies backing them up, said Dr. Gangloff-Kaufmann. They can also provide a false sense of security, Mr. Backenson said.

If you find any evidence of bedbugs, do not stay in the room. Instead, contact the hotel staff, leave the room with your belongings and request a room in another part of the hotel — not adjacent to the infested one.

During your stay

Minimize the places a bedbug could hide by storing your clothes in sealable plastic bags. Some travelers also bring large, airtight plastic bags for their luggage.

A hard suitcase, Mr. Backenson said, may be a safer choice than soft luggage because it has fewer crevices where bedbugs can stow away. Always keep your luggage on a rack, away from the wall, or in the bathtub.

Do not sprinkle diatomaceous earth — a white, silica-rich powder that some travelers have deployed to desiccate bedbugs — in a hotel room, Dr. Gangloff-Kaufmann said, because it may contaminate the room and potentially even cause a scare if a hotel worker sees it and doesn’t recognize it.

Blasting your luggage or clothes with a hair dryer or a portable steamer, another popular tip, may not work because the temperature may not be high enough for long enough to kill the insects, said James Mulloso, vice president of Northeastern Exterminating in Brooklyn. Their eggs may take up to 90 minutes at 120 degrees Fahrenheit to destroy, the E.P.A. says on a web page for bedbug control.

Wiping down your suitcase with rubbing alcohol, another popular bedbug-fighting strategy, can help kill the insects if done safely in a well-ventilated area, Mr. Mulloso said, but keep in mind that rubbing alcohol is flammable, and it could be dangerous.

After you return home

After your trip, unpack your bags in the bathroom against a light-colored surface, so you can spot any bugs, the New York City Department of Health advises, then shake out the clothing in a bathtub or shower and vacuum out your luggage. Don’t forget to empty the vacuum and dispose of its contents.

Put your clothes in the dryer as soon as possible, the experts agreed, and run it at the hottest setting for at least 20 minutes to kill bugs and eggs.

If you think an item has been exposed to bedbugs and it cannot go in the dryer, seal it in an airtight plastic bag and leave it in a warm area for six months — the time it takes for the bugs to die from lack of water, Dr. Gangloff-Kaufmann said.

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AT&T offers the International Day Pass for $10 a day, allowing travelers to use their phones much as they would in the United States. AT&T automatically adds a day pass when customers with unlimited plans connect to the network in a foreign destination.

Customers with this plan can use their phones for as many days as they want, but they’ll be charged only for a maximum of 10 days per billing cycle. The plan covers about 210 destinations. (Canada and Mexico are included in unlimited plans.) Some exceptions: Cuba and the Maldives.

Verizon has a similar offer: TravelPass, which gives customers who have Unlimited Plus, Unlimited Welcome and other unlimited plans the ability to talk, text and use data for $10 per day (there is no cap on how many days you can be charged in a billing cycle), or a monthly $100 pass. The first 2GB of high-speed data each day is included; after that, travelers get unlimited data at a slower speed.

Unlimited-plan customers heading to Canada or Mexico do not need to buy TravelPass, but for all other plans, a day pass for those countries costs $5. TravelPass covers about 210 international destinations. Exceptions: Cuba and the Maldives.

T-Mobile automatically includes international coverage at no extra cost in its most popular plans, said Mike Katz, president of marketing, strategy and products. Depending on the plan, it includes unlimited texting in over 215 destinations worldwide and 5GB of high-speed data per billing cycle (but most phone calls cost 25 cents a minute). As with AT&T and Verizon, Cuba is not covered, but the Maldives is.

T-Mobile travelers needing more high-speed data or free calling can upgrade with day passes, starting at $5 (unlimited calling, and up to 512MB of high-speed data). For longer stays, a 30-day plan with up to 15GB of high-speed data costs $50.

Swap your SIM

Subscriber identity module cards — tiny, removable chips that link a phone to its owner’s network and phone number — offer another way to save money while you’re traveling, especially if you’re taking an extended trip or using a large amount of data. Instead of signing up for a U.S. provider’s international calling plan, you can buy a local SIM card, usually as part of a pay-as-you-go or prepaid package, usually at a cheaper rate. Rates vary depending on the provider, country and offerings.

If you have a newer model of phone, you probably don’t even need to swap out — and keep track of — physical SIM cards: You may have built-in eSIM capabilities instead.

Apps like Airalo provide affordable eSIM options for hundreds of destinations around the globe. Airalo’s options include Discover Plus, a global plan that includes 10 text messages, 10 calling minutes and 1 GB of data, starting at $15 for seven days. There is also a regional plan (covering places like Europe), starting at $5 for seven days, and a local plan (for only one country), as low as $4.50 for seven days.

Two caveats to SIM swapping: Your phone generally must be unlocked (not tethered to a specific carrier), and you will usually receive a foreign phone number when you set up the new SIM card, so make sure to share that number with anyone who needs to contact you. (Your regular phone number will go to voice mail.) If you use an eSIM and your phone has Dual SIM Dual Standby technology, you may still be able to use your regular number.

Tailor the technology

There are a few technological precautions travelers can take to avoid bill shock.

First, control your data use by turning off data roaming in your phone’s settings when you don’t need it. You can also download maps when you have Wi-Fi and then use apps like Google or Apple Maps in offline mode. You can also squelch data-gulping apps individually by toggling off their access to cellular data in your phone’s settings.

Finally, consider using secure Wi-Fi (be wary of public networks) to make calls on services like FaceTime or WhatsApp to avoid voice or long-distance fees.

If a heat wave has been forecast at your destination, check government websites before embarking on your trip to give yourself plenty of time to plan and adapt. In extreme temperatures, governments often issue heat advisories warning people to stay indoors during peak heat hours and provide resources to help residents and visitors stay cool. In the United States, the National Integrated Heat Health Information System has a website with information and tools to help prevent illness and death during excessive heat.

Tourist attractions also provide important updates about the conditions at the sights, including any scheduled closures, as a precaution against high temperatures. Some cities grappling with intensive heat, like Los Angeles, Miami, Athens and Melbourne, have assigned chief heat officers to prepare for the heat waves and lead emergency responses.

Avoid peak sun hours

It may seem obvious, but staying outdoors for prolonged periods of time when the sun is at its peak can put many at risk of heat exhaustion. Even if the temperature does not read exceptionally high, excessive dry heat or humidity can make an environment feel hotter than it is.

Travel advisers are adapting itineraries, putting sightseeing in the cooler early morning and evening hours and prebooking tickets for their clients so they do not have to wait in long lines.

“We tend to do activities and tours in the morning, then stop for lunch, and in the mid- to late afternoon you either go back to the hotel to sit by the pool or go to the beach,” said Gary Portuesi, a co-managing partner at Authentic Explorations, a New York-based travel company that specializes in Europe.

Hiking in the middle of the day is also not advised. On June 5, Dr. Michael Mosley, a British medical journalist, died during an afternoon hike in a 104-degree heat wave on the Greek Island of Symi. Four more tourists, including an American man, have recently died in Greece as temperatures have continued to soar.

“I would always recommend going hiking with a certified local guide and under no circumstances alone,” said Franziska Basso, a Milan-based travel adviser for Dreamsteam Exclusive Travel. “Of course, avoid the hottest hours of the day. Go hiking very early in the morning. And always stick to official hiking trails.”

In some European cities, including Paris and London, air conditioning is not a given, so check if it is available before booking a hotel, restaurant or transportation to ensure you have a cool place to find respite from the scorching heat. Visiting a museum or other indoor sightseeing is another good option, but expect crowds at peak hours.

Stay hydrated and take a siesta

Dehydration and heatstroke are among the most common causes of hospitalization during heat waves and can be prevented by staying hydrated and limiting alcohol consumption. During meals, consider eating foods like melons, cucumbers and celery as it can help to sustain hydration throughout the day. Always carry a water bottle with you and consider a parasol and portable fan to help keep you cool and shaded when outdoors.

While your itinerary may be packed with activities and tours, the heat can take a toll on stamina, so consider following the European siesta ritual by breaking up your day with a short nap.

“I’m telling my clients to adapt their itineraries and take advantage of the after-lunch siesta and then push their tours to later in the day when it’s cooler,” said Sarah Johnson, who owns Paper Ink & Passports Travel, a luxury travel company based in Pennsylvania. “There’s a reason they’ve been doing it in Spain and Italy for generations. Walking around in the midday heat and waiting in line could really hurt some people.”

Wear cool clothing

The National Weather Service recommends lightweight, loosefitting, light-colored clothing for outdoor use as it reflects heat and sunlight. Hats and sunscreen are also recommended to protect the face and scalp from harmful UV rays.

Just because it’s hot, doesn’t mean it will be dry. Heat waves can bring torrential rainfall, so be prepared.

“My biggest advice to travelers is to be prepared — for hot or cold, dry or wet weather since one never knows,” said Laurel Brunvoll, the owner of Unforgettable Trips, a Maryland-based travel agency. “Pack layers.”

Book a flexible trip

Even after taking all the right precautions, traveling in a heat wave can be miserable, making it worthwhile to make flexible bookings and purchase “cancel for any reason” travel insurance to have the option to postpone your trip to a cooler time.

Sensible Weather, a Los Angeles-based start-up that provides a weather guarantee for vacations and outdoor experiences, has recently added high heat protection to its coverage. Travelers booking through a Sensible partner in the United States will be able to add daily protection that will allow them to claim reimbursement for a booking if the temperature exceeds a threshold that is usually set between 90 and 100 degrees.

“Our customers can still go on their vacations, but if it’s too hot for some hours of the day and unpleasant to go outside, you can hang out in the air-conditioning and we will reimburse you,” said Nick Cavanaugh, the company’s founder, who was developing the product while caught in a heat wave in Barcelona last year. Those on package tours are reimbursed for the average daily rate of their entire trip for each day that surpassed the heat threshold.

For more travel advice, visit our collection of Travel 101 tips and hacks.

Regardless of the airline or route, flying an unaccompanied minor differs from an adult or a family catching a flight. Airlines require a trusted pre-authorized adult to be at the departure and arrival gates, and will ask you at booking to provide contact information for those adults. They will also need to present identification at the terminals.

The journey begins at the originating airport’s airline ticket counter. There, airline staff will check your identification and check in the child, perhaps handing them a lanyard or wristband to wear. The agents will provide you with a pass to get through security with your child. You will accompany them to the gate, where you will hand them off to a gate agent. You must stay at the gate until the plane takes off.

In the air, the flight crew will keep watch — but will not babysit, or sit with, your child. If the flight has a connection, a crew member will walk your child off the plane and a gate agent will take him or her to the next gate.

At the arrival airport, the child will be handed off by staff to the authorized guardian or parent who should have already checked in at the ticket counter with proper identification, gone through security with their gate pass and be waiting at the gate.

To learn more about this process, read the Department of Transportation’s online guide, “When Kids Fly Alone,” followed by the website of your selected carrier.

Choosing an airline and paying an extra fee

Before purchasing a ticket, experts advise you to consider an airline’s on-time performance. “Solid on-time performance is hard-earned, and signals a carrier that has tight control of its operation,” said the Ask the Pilot author, Patrick Smith. The Bureau of Transportation Statistics has those numbers.

Booking procedures vary. Delta Air Lines and American Airlines require you to call. United Airlines allows bookings online. JetBlue Airways does online bookings, too, but asks for three printed copies of its forms upon arrival at the airport.

International flights may call for a notarized consent letter describing where the child is traveling, with whom they’ll stay and how long they’ll be there.

On top of the ticket fare, flying an unaccompanied minor can be pricey.

Southwest Airlines charges $100 one way for each child, regardless of distance. Alaska Airlines charges $50 per child if the flight is nonstop; a connection adds $25. On Delta, one $150 fee will cover up to four children, and American’s $150 covers all siblings, with no cap on number. United charges $150 for one child, or two children flying together.

Restrictions: There are plenty

U.S. carriers allow children to fly as unaccompanied minors once they turn 5 and before they turn 18. But regardless of your child’s age, make sure he or she is ready by discussing the trip details and your expectations of their behavior. No policy can replace your judgment.

The low-cost carriers Frontier Airlines and Allegiant Air don’t allow unaccompanied minors, Other airlines have restrictions that, in the broadest terms, differentiate between young children and teenagers. American and Delta restrict children under 8 from routes requiring connections. Both airlines allow children between 8 and 14 to take some connecting flights.

On American, no unaccompanied minor is allowed to take an overnight flight requiring a connection, or a flight that includes a connection on its final leg that also happens to be the last such flight that day (“unless it’s the only flight,” the company adds). Minors are not allowed on code-share flights.

United and Delta have similar rules. Southwest, JetBlue and Spirit don’t allow unaccompanied minors on connecting flights.

JetBlue prohibits minors from flying to Europe, and limits the number of unaccompanied minors in one party to three. Spirit does not allow children on flights to Central or South America. Southwest doesn’t allow children on any international flights. American, United and Delta let minors fly abroad, but restrictions on connections, code-shares and overnights limit options.

Opting out

American and Delta allow children to opt out of flying as unaccompanied minors once they turn 15 — that is, the child can fly without the assistance of airline personnel. JetBlue ends unaccompanied minor service at 14, while Alaska has an opt-out option at 13. Southwest boasts the lowest opt-out age: 12.

However, you should be able to accompany your child to the gate even if they’re not flying unaccompanied. American requires that you do so for teens between the ages of 15 and 17, even if they’ve opted out.

What to pack

Have a plan to head off your child’s hunger, boredom and thirst. If they are older, make sure they have emergency money and a charged phone.

When her two daughters, then 9 and 11, flew to Denver, Joey Conover of Charlottesville, Va., had a long list for their carry-ons.

“Pack a backpack with iPad, headphones, lightweight book to read, a pad of paper and colored pencils (markers might smear), a small travel game, water bottle (bring empty and fill in airport), snacks, some kind of surprise fidget or animals to play with, hoodie, and a lovey,” she wrote in an email.

“Write your name and phone number on the inside of their arm in Sharpie and put a parent’s business card in a luggage tag on both suitcase and backpack,” Ms. Conover said. (A sheet of paper with all their identification, and their guardian’s contact information, also works. Simply stick in an easy-to-access pocket.)

The company said that more than 16,500 properties, a combination of hotels and rentals, have separate, third-party sustainability certification.

The vacation home rental platform Vrbo does not have an eco-friendly search filter, citing the lack of industry consensus on what makes a rental more sustainable. Properties listed by its sibling agency Expedia may say they are “eco-certified” and users can search using that filter. But read the results carefully; some listings lack information on their sustainable features.

Wherever you search, scrutinize the listings, said Bob Garner, the founder of EnviroRental, a service that works with short-term rental owners on sustainability practices. Do bathroom photos show shampoo in large, shareable dispensers? Does the description mention recycling? If the host has a separate website, look for press links or blog posts related to sustainability.

Talk to the host

According to Airbnb, more than 80 percent of its hosts say they incorporate at least one sustainable feature, such as composting, minimizing single-use plastics and providing guidance on using public transportation. The platform maintains a guide for hosts on sustainable tourism practices, with tips on things like creating a manual to direct travelers to local shops, restaurants and markets.

“When you think you’ve found the right property, ask some questions,” Mr. Garner said. “If they can’t answer them, then there’s a red flag.”

Just the act of asking about environmentally friendly features can have a lasting effect.

“If they think you care, there’s a greater chance of moving the needle,” said Diane Daniel, the founder of Vacation Donations, a nonprofit that encourages short-term renters to donate leftover food in the Tampa, Fla., area.

Consider a pedestrian- or public-transit-friendly location

Even if you can’t find a solar-powered stay, you can choose a location that allows you to get around with minimal emissions.

Connect your “environmental consciousness with the idea of being a good traveler,” said Beth Santos, the chief executive of Wanderful, a global women’s travel community, and the author of “Wander Woman: How to Reclaim Your Space, Find Your Voice, and Travel the World, Solo.”

She recommends travelers live like locals, including taking public transportation, visiting neighborhoods beyond city centers and patronizing small businesses. Take a “day zero,” or a single unscheduled day to walk the neighborhood to find nearby shops as well as transportation options.

Conserve energy

Conserve energy by turning air conditioning off or down when you’re out, switching off lights when you leave and turning off the tap while you brush your teeth.

“This could be one area where you say, ‘I don’t care, I’m on vacation,’” Ms. Daniel said. But travelers should stay vigilant, she said. “Short-term rentals are the easiest places to regulate your footprint, because it’s really up to you.”

Plan meals, reduce waste

Renters usually have the option of cooking meals. To avoid food waste, plan meals and shop for them as you go — and as plans change — rather than buying everything at once. Bring staples like salt and pepper and ask the host if the kitchen is stocked with other supplies like cooking oil and coffee.

“Buying slowly over the week as you need things is a really nice experience if you’re in a location where they’ve got some nice delicacies and interesting farm shops,” Mr. Garner said.

Ms. Santos of Wanderful recommends packing a collapsible food container. “You can throw it in your luggage, take home leftovers and have a place to reheat them,” she said.

Donate leftover food

Take as much leftover food home as you can and look for food pantries that accept donations for whatever you can’t take.

“Perishables are very challenging unless you’re near a pantry that takes them and is open when you’re checking out,” said Ms. Daniel of Vacation Donations.

Don’t assume the cleaner wants your food. In a pinch, Ms. Daniel recommends knocking on neighbors’ doors if you’re staying in an apartment building, or searching Facebook for local groups seeking food donations.

Consider ‘community offsets’

Carbon offset programs invest in activities like tree farming that reduce carbon in an amount matching the emissions generated by a trip. But it’s a controversial practice that has led to inflated, if not bogus, claims of carbon mitigation.

Instead, consider donating your time to a local cause in the area where you’re renting.

“Community offsets or volunteering work are opportunities to spend two hours one morning of a holiday to help in whichever volunteering work there is in this local area, from picking up trash to feeding homeless people,” said Vanessa de Souza Lage, the co-founder and chief executive of Sustonica.

What can an adviser give me that a booking site can’t?

Travel advisers can help you research the best destinations, lodging, or activities for your particular group and travel goals, offering up specific advice that might be hard or time-consuming to find yourself. Those specializing in cruises might know which cabin to choose if you are prone to seasickness, while a safari planner could help you decide which park would be best for bird-watching or seeing specific animals, like rhinos.

Travel advisers typically have relationships with tour companies, hotels and cruise lines, sometimes through networks. Those connections can allow advisers to offer extra perks such as late checkout, free breakfast, airport transfers, a welcome basket or a credit to spend on a cruise ship.

“A good travel agent will be a better steward of your travel budget than you are,” said Guy Rubin, managing director of Imperial Tours, which arranges travel in China.

When bad weather or other circumstances disrupt your itinerary, travel advisers often have direct lines of communication with providers and can do the work of rebooking and changing plans, saving you time and stress.

OK, let’s say I need help. How do I find an adviser?

Networks like the American Society of Travel Advisors and Travel Leaders have websites that can help you start your search for a travel adviser by answering a few questions about your desired trip. Once you have a handful to choose from, get on the phone with them to talk about what they might do for you, how they charge and the level of service you can expect. Special trips can cost thousands of dollars, so it’s worth investing time up front, Mr. Rubin said.

Make sure to read over the travel agent’s reviews and any user-generated social content that mentions them, Dr. Anderson said. “If there is no external validation, that’s a red flag.”

How do advisers get paid, and how much will it cost me?

Advisers receive commission from suppliers, typically 10 to 15 percent of the price, when selling cruises, lodging and tours. They also sometimes charge travelers a planning fee, from a few hundred dollars, which may be credited to the final bill if the booking is completed, all the way up to tens of thousands of dollars annually for a luxury concierge travel planner they can call on all year. Mr. Johnson said that he charges a planning fee the first time he works with customers. If they return for other trips, he waives the fee.

Advisers may be tempted to sell you something that will earn them a higher commission, Dr. Anderson said. But, he points out, the same is true for the large online services, which promote hotels that pay them larger commissions. Travelers can ask advisers about specific commissions they receive or how they are affiliated with the products they are recommending, he said.

Sometimes a local tour company will package transportation, lodging and experiences for an adviser, who tacks on a percentage before passing it along to a client. But a bill that is not itemized can make it harder to make trade-offs — between a more expensive hotel and a special experience, for example. If pricing transparency is important to you, discuss it with the adviser up front.

How are A.I. and other technologies affecting travel advisers?

While new technologies are allowing do-it-yourselfers to create their own itineraries online based on individual preferences, and to type questions directly into travel websites, advisers are also taking advantage of those technologies to improve their services. Joan Roca, chief executive of the upscale travel planning company Essentialist said his team “uses technology to enhance the human touch,” employing artificial intelligence to choose options from a database of travel offerings selected by a human team. If a couple wants to take an after-dinner stroll, for example, Essentialist’s app will offer up ideas of where to go, based on what part of the city the travelers are in and conversations they’ve had with their travel adviser.

The basic rules for flying a drone as a hobbyist — that is, recreationally using a drone — are to fly the unmanned aircraft only at or below 400 feet, always keep the drone in sight, do not fly in restricted airspace and do not fly over groups of people. If you are flying your drone commercially, you must become a certificated remote pilot by passing the F.A.A.’s Part 107 test. This is a more extensive test and covers additional drone rules, airspace regulations and weather conditions.

Be aware that many countries may have different regulations. Anywhere you go, you may be fined or your aircraft may be confiscated if you do not adhere to the rules.

Understand what your drone can do

Drones are incredibly fast, maneuverable and precise. You can fly up to 400 feet and move laterally in an infinite number of directions to get the perfect shot. But first-time drone flyers often fly as high as possible and take pictures that lack a point of focus or a strong composition.

In order to get photos with the most detail, set your drone to the lowest ISO, usually 100. This is the feature that sets the camera’s sensitivity to light and was known as the film speed back in the days of film. To achieve the best quality pictures, it’s best to shoot in RAW format, which is a digital image file that is unprocessed and contains the most amount of data. When processed, this will produce photographs with the most detail.

After you have purchased your drone, it’s good practice to regularly update the firmware, which is software that provides basic instructions for the craft’s hardware to function successfully, like the drone and remote controller working together.

Use maps and the weather forecast, and time it right

Whether you consult an atlas or follow your car or phone’s navigation, maps are very effective tools for seeing the shape of a river, lake or pond and provide ideas for good aerial subjects.

Once you have a location, shoot during the “golden hours” — taking photos around sunrise and sunset will often produce the most dramatic pictures with warm light and shadows. It’s a good idea to keep an eye on the weather forecast to know the sunrise and sunset times and also what the weather will be. High winds and rainy or snowy weather make flying a drone much more difficult.

Look for patterns, lines and light while flying

Many times a drone photographer will make discoveries from the air. You might launch with the idea of photographing one thing and, while in the air, you might discover something more compelling. Rivers, solar arrays, farm fields and trees can provide engaging patterns and lines.

And don’t forget the light and shadows, either. Good light can make or break a photo. Sometimes the best light means a golden sunrise, as we said earlier, but sometimes it means an overcast day with diffused light. On cloudy days, shooting straight down on a subject can be very effective.

Taking drone photos at twilight can also be very captivating. This is the time after sunset and before nightfall. Set the drone to manual exposure, set the ISO to 100 and experiment with long exposures. Some drones can take up to eight second exposures and maintain sharp focus.

Study an expert’s work

One of the great ways to make your photos better is to study the work of a professional photographer.

The photographer George Steinmetz has been making aerial photographs for decades — even before the rise of affordable drones — while working with publications like National Geographic and The New York Times. He has published five books on aerial photography.

“For intimate aerial photography, a drone is exceptional,” he said, but adding that any type of aerial photography can be transformative.

“You see the world in a way you’re not accustomed to,” he said. “It adds context and a new perspective.”

Check out the National Interagency Fire Center’s National Incident Map, FireWeatherAvalanche.org and CalTopo.com for real-time fire maps. You may also want to follow the social media accounts of the cities, counties and parks you’ll be visiting, as these accounts often deliver real-time information.

Prep your phone

Your device could save your life in a wildfire, but not if its battery is dead. Ensure yours works when you need it by bringing a charger that doesn’t need a wall or a car socket, such as one powered by the sun.

Both FEMA and the American Red Cross have free apps that you can customize to receive location-specific alerts. On the Red Cross app, there’s also an option to enable critical notifications to sound, even when the phone is on silent or in Do Not Disturb mode.

Candice Stevenson, a fire communication and education specialist for the National Park Service, advises signing up for emergency alerts for the area you’re visiting. These alerts might be shared via text, email or phone call, depending on where you’re traveling. “Sometimes,” she wrote in an email, “a text or alert can still work while in poor cell coverage.”

Another tool for low- or no-service areas is What3Words. The free app works by dividing the world into roughly 10-by-10-foot squares and assigning a unique three-word code to each square. (The geocode for the trailhead for the path leading to the top of Half Dome, in Yosemite National Park, for instance, is songbird.contraband.partly.) Because the service uses satellites, your phone can receive the three-word address corresponding to your location even without internet or cell service, which can help emergency workers find you when you do make contact with them.

“I can’t tell you how many times people will call and say, ‘I’m on fill-in-the-blank lake,’” said Alex Luscutoff, the deputy chief of law enforcement and emergency services for California State Parks. “When we get that information as first responders, sometimes it’s very difficult to distinguish what particular area of the park they are located.”

Use of the service is catching on. Besides the California State Parks, emergency responders in and around places like Austin, Texas; Niagara Falls, Ontario; Tucson, Ariz.; Los Angeles, Nashville and London have also adopted the app.

Bring analog backup

Phones are powerful tools, but they can also break, freeze up or get dropped in lakes.

Don’t underestimate the value of paper maps. Study them before you depart to familiarize yourself with your destination, and to find several evacuation routes. Then, keep those (preferably waterproof) maps handy.

Sherri McKinney, a national representative for the American Red Cross, also recommends bringing a lightweight hand-cranked weather radio, especially for backcountry travel, to listen for weather information and emergency announcements. A hand-cranked radio “can be the difference between life and death,” she said.

Be ready to evacuate

Once a fire starts, time is limited. “Fire is fast,” Dr. Moore-Merrell said. “It is fast when it is coupled with hurricane, gale-force winds as we saw in Maui; it is fast if it happens in your home.”

That means it’s critical to know your evacuation route before a fire starts. When you reach your destination for the night, Dr. Moore-Merrell said, look for exits, stairwells and any other escape routes. Better yet, Ms. McKinney advised, once you arrive and drop your bags, “take another drive after you’re checked in so that you can see what the exit route is, and practice that evacuation route.”

Above all, if and when you’re told to evacuate, don’t wait — get out.

Get to a safety zone

Maybe you’re too far from your car to reach it. Maybe you’re too deep in the backcountry to reach a road. Maybe the fire is blocking your only escape route.

If, for any reason, you cannot evacuate, look for a safety zone: a place where you could survive a wildfire and await help.

Ms. Stevenson of the National Park Service wrote that what constitutes a safety zone depends on a fire’s severity: “The larger the flame heights and the faster the wind speed, the larger the safety zone would need to be.”

If you’re on a hill, Drew Leemon, the risk management director for the National Outdoor Leadership School, advises going downhill. “Heat rises, so it’s going to go up the side of a valley faster than you can run,” he said.

Mr. Leemon also suggests heading for a body of water, ideally one deep enough to submerge yourself, if there is one nearby.

Fire needs fuel, so get away from as much fuel as you can. If you’re in the forest, he said, go to a meadow. Better yet, run to a place with very little vegetation, like a boulder field or a rocky area. If you’re in immediate danger, Mr. Leemon said, you can head into “the black” — the area that has already burned. That scorched zone presents its own risks — embers, hot ground and trees that might fall — but there is also much less left to burn there.

“My advice for a first-time camper is take small steps,” said Alyssa Ravasio, the founder and chief executive of Hipcamp, which lists campsites on private land such as farms and ranches. “Try a night or two. Go somewhere closer to home. And make sure the amenities that are important to you, such as a bathroom or shower, are there.”

Reserve in advance

Like hotels, many campsites can be booked online. Reserve your spot in advance, especially in peak seasons. At New Hampshire State Parks, for example, reservations open 30 days in advance with just a few campsites held back for day-of arrivals.

The federal website Recreation.gov offers campsite reservations across many government agencies, including the National Park Service.

If you aim to camp at a popular national park, plan well in advance and get familiar with its booking rules, which are not standardized, by searching park websites or Recreation.gov. Campsites at Upper Pines Campground in Yosemite National Park in California, for example, are available five months in advance. In contrast, sites at South Campground in Zion National Park in Utah are bookable up to 14 days before arrival.

If national park sites are booked, look for nearby state parks or alternative campgrounds. Hipcamp offers maps showing public lands, including national parks, and many places to camp around them.

Commercial campgrounds like KOA may offer amenities such as swimming pools or basketball courts. Websites like ReserveAmerica.com make it easy to find both public and private campgrounds. Booking platforms such as Hipcamp, the Dyrt and Pitchup.com are good places to look for off-the-beaten-path options or privately owned properties.

If a campground is booked, set up an alert with the Dyrt, which will text you if a site becomes available. The service starts at $9 for nonmembers.

Rent camping basics

When it comes to basic gear, rent before you buy.

“Gear can be pretty expensive,” said Ms. Ravasio, who recommends renting from an REI Co-op store. Other companies such as Outdoors Geek and Kit Lender will ship gear.

“With tents it is worth noting that a four-man tent won’t comfortably fit four men in reality,” said Dan Yates, the founder of Pitchup.com, noting that tent sizes don’t account for baggage. He recommends choosing a tent sized for two people more than will be sleeping in it.

Sleeping bags, rated for outside temperatures, are also often available to rent. Most guides recommend adding a sleeping pad or mat.

“We can deal with almost anything during the day if we get a good night’s sleep,” said Gary Elbert, who designs camping trips for REI Adventures. “If I’m investing money in something, it’s a sleeping kit.”

Plan the kitchen

With a vehicle, avoid buying specialty cooking gear and pack small pots, pans, plates and utensils from home. If you don’t want to cook over an open fire, rent a camp stove.

Food storage advice depends on where you camp. Where bears are not present, storing food overnight in your car deters animals such as raccoons. In bear country, follow campground requirements and use provided food storage safes. Depending on the location, the National Park Service recommends storing food in a locked car only during the day with food or food storage containers such as coolers covered and windows closed.

Water is a primary survival need. In its guide on what to bring, the National Park Service recommends two liters of drinking water a person a day and more if you are in hot places. The Green Mountain Club, a nonprofit that manages 500 miles of trails in Vermont, recommends adding two liters for cooking and another two for extinguishing a campfire.

“Most developed front-country campgrounds will have a potable water source, so be sure to check before you go,” said Emily Mosher, the visitor services manager for the Green Mountain Club.

Pack for problems

Pack and dress in layers to account for changes in temperature from day to night, and remember rain gear or a water-repellent outer layer. Avoid cotton, which absorbs water, including perspiration, and is slow to dry.

Bring a headlamp, which allows you to do things hands-free in the dark like unzip your tent. A utility knife or multi-tool device helps with chores. A first-aid kit should be stocked with bandages, antiseptic wipes and pain relievers.

To account for no or low connectivity, bring paper maps or download maps that you can review offline.

It’s not all defensive packing. Don’t forget cards, books and games.

Practice fire safety

One of the great joys of camping is sitting around a campfire. Campers should check with park or campground authorities to ensure fires are permitted; in drought conditions they are often banned.

Only burn wood that has been purchased or provided locally — firewood from other places risks transporting invasive insects or diseases.

There are several ways to build a fire, as covered in this guide from KOA. Using the basic tepee or cone structure, lean small sticks against a bundle of starter such as dry grass or birch tree bark. Once the tinder is ignited and the sticks catch fire, add increasingly larger sticks, working up to logs.

The most important step in breaking camp is to ensure your fire is out. According to the Department of the Interior, almost nine in 10 wildfires are caused by humans.

When you douse a fire, make “campfire soup” by drenching the fire pit in water and stirring it with a stick so that it reaches all the coals. The remains should be cool enough to touch before you leave.

Leave no trace

Collect all garbage and dispose of it or take it home. Strain gray water used to wash dishes and drain the water in collection areas.

The nonprofit conservation organization Leave No Trace offers a free 45-minute online tutorial in safe and eco-friendly camping basics.

Feel welcome

Outdoor lovers in historically marginalized communities have created organizations that encourage hiking and camping with events, trips and how-to videos. Look for educational resources at Black Folks Camp Too, Latino Outdoors and the Venture Out Project, among others.

Travel insurance was designed to protect expenses you can’t get back any other way when things go wrong. Think of nonrefundable Airbnb reservations or the cost of a cruise to the Galápagos.

If your hotel is refundable and you can get the value of your flights back in credits, you can skip travel insurance.

Buy close to booking

Travel insurers say the best time to buy travel insurance — which usually takes effect within a day of purchase — is just after making your travel plans to have the largest possible coverage window. A lot can happen between booking a Christmas market cruise in Europe in June and going in December.

With many plans, purchasing travel insurance 10 to 14 days from your first trip payment entitles you to “early purchase” benefits such as a waiver for pre-existing medical conditions that impact travel. If such a waiver is included, it is usually prominent in a summary of benefits, so read it carefully.

“Not all plans have a pre-existing condition waiver,” said Suzanne Morrow, the senior vice president of InsureMyTrip.com, an online insurance marketplace. “If I have a heart condition and if something occurs, I don’t want it excluded, so I would need to buy a policy within 14 days of the first dollar spent.”

Hedge against the weather

You can’t control the weather, but you can insure against its unexpected disruptions. For example, if you’re ready to jump on great rates in the Caribbean during the height of hurricane season, buy your insurance immediately after booking so that if a hurricane develops and your destination is evacuated, you’ll be covered.

“That’s probably the biggest use case for travel insurance,” said Stan Sandberg, a co-founder of TravelInsurance.com, an online marketplace. He counsels travelers to buy early — if you wait and the storm is named it will be too late to insure against it, because it is no longer an unforeseen event.

Similarly, with winter travel, if you’ve purchased nonrefundable ski lift tickets and a storm prevents you from reaching the resort, you may be able to claim the unused portion of your ski pass.

This coverage may prove more valuable as climate change exacerbates weather events like hurricanes and tornadoes, which are considered “natural disasters” and are covered by most policies.

Pick up the phone

With the proliferation of automated insurance offers when you buy airline tickets or tours, travel insurance can feel like a one-size-fits-all product. It is not. Many policies, for example, exclude extreme sports like skydiving and mountain climbing, though there are specialty policies that include them.

If you have a specific concern — a family member is sick or you’re going heli-skiing — the best way to know if a travel insurance policy will cover you is to call an insurer or the help line at a travel insurance marketplace to get advice.

“Tell them the what-if scenario and then you can get professional and accurate advice,” Ms. Morrow said. “Thinking you’re covered and then having your claim denied is salt in the wound.”

Travel insurance does not cover ‘unpleasantries’

What if you’re dreading spending a week in an un-air-conditioned rental in England during a heat wave and decide you don’t want to go? Most standard travel insurance will not cover a change of heart.

“Travel insurance doesn’t cover you for unpleasantries,” said Carol Mueller, the vice president for strategic marketing at Berkshire Hathaway Travel Protection.

A policy upgrade, Cancel for Any Reason coverage, which is not available in every state, will cover a change of heart, usually up until a few days before departure. Most only reimburse 50 to 75 percent of your costs and the purchase must be made within weeks of your initial trip payment. It will bump your insurance premium up 40 to 50 percent, according to the insurance marketplace Squaremouth.com, which only recommends C.F.A.R. for travelers with specific concerns not included under covered reasons for trip cancellation.

A relatively new twist in trip protection, Interruption for Any Reason, works like C.F.A.R. in that it reimburses a portion of your expenses and can be invoked if you decide to bail while you’re on a trip for a reason that isn’t covered by standard trip insurance. Normally, you must buy it within weeks of your initial trip payment and be 72 hours into a trip before you can use it.

Keep records

If something goes wrong and you need to make a claim, you’ll need proof in the form of a paper trail. That could be receipts for clothing you purchased when your bags went missing, a hotel room required when your flight was canceled (along with flight cancellation notices from the airline) or a doctor’s note stating that you have Covid — or another illness — and are unable to travel. (With Covid, a positive test taken at home is not considered official documentation for the purposes of a claim.)

Resist pressure to buy flight insurance

When purchasing an airline ticket online, most carriers offer travel insurance to cover the cost with some version of vaguely menacing language like, “Do you really want to risk your investment?” when you decline.

Don’t fall for it. You may want to insure that ticket, but price out the policy elsewhere. A recent offer to insure a $428 flight for nearly $28 on an airline website cost $12 to $96 with a range of options at InsureMyTrip.com.

The $12 option was closest to the airline’s offer. Caveat emptor.

Harness the power of light

Bright light helps keep our internal clock in sync with the outside world, traveling through specialized cells in the retina and signaling the part of the brain that sets the body’s master schedule. So, for longer trips, seek out or avoid bright light at specific times, said Dr. Olson. Starting a few days before your trip, gradually shift the light and dark times of your origin toward that of your destination, using dark glasses, sunlight or other light sources.

In the first few days of your trip, figuring out the best times to get light can be tricky. Let’s say you take an overnight flight from New York to London, arriving at 7 a.m. Your brain may still feel as if it’s 2 a.m., and getting bright light right away could confuse your internal clock. In this case, you may want to put on dark glasses for a few hours, then go out in the sun when it is closer to your waking time at home, extending your London day.

On long trips to Asia — when day and night are reversed — it is often easier to shift your cycle backward, said Mickey Beyer-Clausen, chief executive of Timeshifter, which makes a jet lag app of the same name. For example, when flying nonstop from New York to Tokyo, which is 13 hours ahead, think of it as being 11 hours behind (jet lag does not consider the international date line). That means if you land at, say, 2 p.m. in Japan — 1 a.m. in New York — you need to counter the fact that your New York brain is winding down for sleep. This means seeking out bright light all afternoon, especially in the evening, until bedtime in Japan. You can also get a head start on adapting to Japanese time if you go to bed and seek out light later than normal for two nights before you leave New York.

Online tools like Jet Lag Rooster and Timeshifter help create a customized schedule based on variables like time zone differences, departure and arrival times, and other factors.

Consider melatonin

If you are having trouble getting to sleep earlier in anticipation of traveling east, Dr. Kapur suggests taking one milligram of over-the-counter melatonin about four hours before bed, up to three days before the trip. (Melatonin is a substance that is produced naturally in the body as night falls, signaling that it is time to go to sleep.) This small dose is best for reducing jet lag, Dr. Olson said, because studies show a larger dose doesn’t necessarily work better and is more likely to produce side effects. Travelers should be aware that as a dietary supplement, melatonin is not regulated by the Food and Drug Administration.

Grab a quick nap

If you’re feeling drained as your body adjusts to the new time zone, curl up for a 20-minute snooze, said Dr. Kapur. If you nap longer than that, he cautions, the brain fog may worsen or you may have trouble falling asleep at night.

Refresh with a layover shower

A spritz at the airport between long flights can work wonders for a tired body. Airports with public pay showers include Tokyo Narita International Airport, Munich Airport and San Francisco International Airport. At some airports, only specific lounges — like the Delta Sky Club at Seattle-Tacoma International Airport — offer showers. If you’re not a member, don’t have access through a credit card and really need a boost, consider a day pass. The IGA Lounge in Istanbul International Airport, for example, costs $65. All offer towels, soap and shampoo.

Make the most of the lag

If you expect to be up super late or early as your body adjusts, plan ahead. Early in the trip, you may have the most energy for a visit to the Patpong Night Market in Bangkok, the early-morning tuna auction at the Toyosu Fish Market in Tokyo or a predawn excursion to see the sunrise at Haleakala volcano in Maui.

At even the hottest restaurants, solo diners without reservations can sometimes squeeze in at the bar. And singles can often snag discounted seats at shows and performances by looking for just one ticket close to showtime, says Kat Fleischman, 36, an American public relations professional who has been taking international solo trips since she was 18. She also advises travelers to inquire about single-occupancy discounts at hotels. Travelers on their own can also hop into faster-moving singles lines at amusement parks, filling in spots left empty by groups. Universal Studios Hollywood and Six Flags Magic Mountain, near Los Angeles, and Disney World, in Orlando, Fla., all have a handful of rides with singles lines.

Join group activities

Websites like Meetup and Fun JetSetter can help break the ice with others who share your interests. An internet search can reveal an array of options: Book dinners with locals and other travelers on the website Eatwith. Find fellow nature lovers through local groups like Alaska Outdoors, in Anchorage, which organizes hikes. Find new places to enjoy your favorite activities through sites like Pickleball NSW in New South Wales, Australia. Facebook groups devoted to people living abroad, like Spain’s Expats of Málaga group, can offer local advice and people to meet.

Some hostels and guesthouses also organize outings. You might find yourself going to a kayaking lesson, a singalong, a drag show or a dance club. The hotel chain Selina, for example, offers co-working spaces along with group outings in more than 100 locations in countries such as Peru, Israel and Thailand.

Talk to the locals

If you are eating alone, sit at the bar, where you are more likely to strike up a conversation with those around you. One trick: “Sit with an English-language book to attract other English speakers,” Ms. Ray said. Some dating apps have “friend” settings that solo travelers can use — take the usual precautions, of course, by meeting in a public place and telling others where you’re going and with whom.

Don’t overshare, and use a financial ‘safe word’

Be cautious about sharing personal information, accepting invitations or leaving your belongings with someone you just met. And consider packing a rubber doorstop to add an extra layer of security to your hotel room or Airbnb, and a loud key chain alarm, Ms. Ray said.

If you’re lost, Ms. Fleischman advises, instead of standing on the street to consult your phone, step into a cafe or a store. And rather than looking at your route on your phone as you’re walking, use your earbuds to get directions from mapping apps.

Come up with a term that only you and a chosen few people back home know, so that if you are genuinely in trouble and need money, they’ll know it’s not a criminal impersonating you. Leave an electronic copy of important documents like your passport, health or travel insurance, and itinerary with those people, too. You may also want to share your location with them using a cellphone app.

Leave space for spontaneity

“Stepping out of your comfort zone and embracing the unusual can lead to some of the most memorable experiences during your solo travels,” Ms. Ray said. Make plans that you can choose to change.

Keep a journal

Solo travel is an opportunity to “foster and cultivate your own sense of empowerment,” said Ms. Ray, and it will help to understand what you’ve learned if you keep a record — written, audio or video — of your goals, setbacks and triumphs.

For sorting out flight arrangements, Robert Driscoll, who owns the L.G.B.T.Q.-focused travel agency VentureOut, swears by TripIt. After making your bookings, you can forward your confirmation emails to the app, which puts them all together on one timeline. Others in the group can then collaborate with the same trip by adding their own bookings to create a group itinerary. “It’s basically a chronological compilation of all your arrangements: flights, accommodations, car rentals, restaurants, activities, tours,” he said.

Commit cash up front

When one participant on a friend trip suddenly drops out, it can throw financing for the whole trip into disarray. Hedge against those monkey wrenches by setting a firm deadline for a monetary commitment. When people put down real money, whether for lodging or activities, they’re more likely to follow through.

Trade off the captain’s hat

Use a classic schoolteacher’s trick to keep everyone engaged and share the planning burden: Schedule a rotating group leader to take ownership of each day’s activities. This person will be responsible for making that day’s restaurant and tour reservations, or simply keeping everyone on schedule. Ask each friend to share a personal desire for the trip — for example, a tour of a museum or an afternoon at the beach — and assign that person to lead the group on the day of that activity. By making everyone the driver, everyone also gets the chance at some point to sit back and be a passenger.

Automate the money flow

Tracking expenses for a whole group can expose a lot of pain points. Differing price sensitivities and priorities make things complicated enough, and that’s before you get into the challenges of pricing couples versus singles, people who join late or stay longer, or charges in multiple currencies. “I have seen so many friendships dissolve because resentment builds when one person suspects other friends are taking advantage of her financially, or not pulling their weight,” said the friendship coach Danielle Bayard Jackson, who is based in Tampa, Fla.

Apps can help make complicated calculations easy and transparent, even while the trip is still underway. Mrs. Jackson said she liked TravelSpend, which automatically converts currencies, and Splitwise, which integrates with Venmo, to “help groups manage everyone’s tabs so there’s no confusion about who owes what.” For divvying up restaurant bills, Ms. Irvin-Choy said she recommended the app Tab, which uses a picture of the receipt to track each diner’s responsibility.

Avoid the ‘travel amoeba’

Groups can easily become what Dina Vaccari, a Seattle-based traveler, calls the travel amoeba: “an excruciatingly slow-moving blob of people that doesn’t really get anywhere.” There are countless situations where the group may end up stalled — when one member runs back to grab a lost hat or needs to use the bathroom or stop at an A.T.M. Decide as a group ahead of time that it’s OK not to wait and set a time and a place to meet up again. Or use the location-sharing feature of apps like WhatsApp, so that stragglers can catch up on their own schedules and the rest of the group is free to keep exploring.

You can use Google Maps, Waze and MapQuest for initial accessibility research using photos and street view. Google Maps provides directions for some wheelchair-accessible pedestrian and transit routes.

Sites such as Roadtrippers and Furkot can plot an entire itinerary. While these websites are not disability specific, they are invaluable tools. (Roadtrippers does have a wheelchair-accessible check box in the search function.) You can filter by types of destinations such as national parks or museums, and search for hotels and campgrounds. Furkot allows you to input how long you want to drive each day, whether you want to travel on Interstate highways or take more scenic roads. The app will determine the best route and length of time between stops, and suggest where to stay overnight.

Finding lodging

While hotels and other accommodations are required to comply with the Americans With Disabilities Act, many hotels do not meet all accessibility needs. Most of the booking sites list hotels with accessible rooms for those with mobility, hearing and vision needs, but this information is not always verified. Do additional research on review sites and look for photos. Hyatt, Marriott, Hilton and Fairmont hotels offer allergy-friendly and scent-free rooms in some locations. Call the hotel to verify accessibility and to make sure a specific room is reserved for you.

Vacation rentals are typically not required to be A.D.A. compliant, but some do provide accessibility information. Airbnb recently rolled out an adapted category with accessibility search features and homes that have been scanned for accessibility. Review photos and contact the host for more information. Some hosts will make accommodations, such as changing the cleaning supplies or shifting furniture, but document your request using the in-app messaging system so that customer service can help if you run into issues.

Wheel the World is an accessible travel agency offering bookings at over 3,000 verified accessible hotels in the United States. The hotels have been reviewed in person by trained assessors; only those that meet the criteria are listed. Sign up as a disabled traveler or a companion and complete a personal profile that includes options for a variety of disabilities and accessibility needs. The site will provide listings that match your profile with partial, adequate and outstanding match options.

Food and medication

There are a variety of options to keep food or medication cold while traveling. Electric coolers can plug into your vehicle’s 12-volt outlet, but pay attention to the type of cooling mechanism — the less expensive versions are usually thermoelectric and will cool only to about 30 degrees below ambient temperature (if it is 70 degrees in the car, it will cool to 40 degrees). Compressor coolers are more expensive but maintain normal refrigerated temperatures.

Many hotels provide mini-refrigerators. When you know you will be stopping somewhere with a fridge almost every night, layer large ice packs and supplies in a cooler, then top them with another insulating layer like a cooling bag. This keeps everything cold for a couple of days at a time.

It’s also a good idea to travel with a single-burner cooktop — electric to use inside, or propane to use at rest areas and campgrounds — and a camp mess kit so that you can safely cook meals.

Some of the best apps to find food, restaurants and grocery stores that accommodate dietary needs are Fig for allergy-specific options, Happy Cow for vegan-friendly options and Find Me Gluten Free for celiac-safe spots. Add your favorite options to the route-planning app so that you know where to stop.

Finding activities

In addition to the apps mentioned in the route-planning section, state and local tourism organizations are good sources for accessible destinations.

National parks and monuments, which are required to meet federal accessibility guidelines, typically have visitor centers and recreation sites with accessible features. Each park website has information, as well as programs and services within the park. While accessibility varies, you can usually find information on wheelchair-accessible trails and campsites, tactile and audio features, assistive listening devices, and American Sign Language interpreters.

At state parks, accessibility features may not be consistent, but you can usually find some information on each park’s website.

Apps like AllTrails list wheelchair-friendly trails across the country, but the information may not be verified, so contact the park or land manager for verification. Among the parks with notable accessible trails are Redwood National and State Parks, North Cascades National Park, Badlands National Park, and Great Smoky Mountains National Park.

Syren Nagakyrie, the founder of the nonprofit Disabled Hikers and the author of “The Disabled Hiker’s Guide to Western Washington and Oregon” and “The Disabled Hiker’s Guide to Northern California,” among other guidebooks, leads group hikes and conducts assessments throughout the United States.

“I tend to maybe throw in a necklace,” Ms. Frommer said, which she wears on top of her day clothing “to make it look more dressy.”

Choose your bag

There is no perfect carry-on for everyone. To determine the bag that’s best for you, ask yourself how you’ll be using it. Will you be carrying it long distances, through subway turnstiles and city streets? Or will you typically be rolling off a plane and into a car? Bags with wheels tend to be less taxing on your body, though if you’ll be taking public transportation or flights of stairs, a backpack or lightweight duffel can keep you hands-free and may make for smoother transitions. Also consider the things you’ll be bringing. Structured, harder luggage is often best for keeping dress clothes wrinkle-free and organizing unwieldy items like high heels. That said, a soft duffel bag without wheels has a better chance of being able to squish into an overhead bin.

Nerissa Settie, who, as the butler executive at Raffles Doha in Qatar trains the butler team and oversees day-to-day operations, wrote in an email that “each option offers a different benefit,” with duffel bags providing more depth, and wheeled bags providing more compartments and less strain on your shoulders. If you opt for the latter, buy a bag with four wheels, Ms. Settie advised, which is easier to maneuver along an aircraft aisle.

Whatever bag you choose, know the rules. Carry-on bag dimensions vary by airline, so be sure to check your specific airline’s size and weight requirements, including those of any connecting carriers.

Also pay attention to your route and fare class, which can affect the number of bags you’re allowed to carry on, as well as their weight. And remember: While your bag may comply with the carry-on policy, that doesn’t necessarily mean you’ll be allowed to bring it on. For instance, if you’re in a low boarding group, you’re more likely to have to gate-check your bag. With that in mind, keep essential items like medicines in a small bag that can easily fit under the seat in front of you. If you’re unsure about whether you’re allowed to pack a particular item, check out the government websites for the places you plan to travel through, such as the Transportation Security Administration’s What Can I Bring? page and the European Commission’s Information for Air Travellers page.

Know when to fold ‘em

When it comes to packing your clothes, the question is: Should you fold them flat or roll them? Ms. Settie recommends rolling because it uses less space and results in fewer creases. That’s easy enough with T-shirts, but what about a suit jacket? The butlers at Raffles Doha use a technique that involves turning one shoulder of the jacket inside-out and then tucking the opposite shoulder inside it, aligning the sleeves and then folding the jacket in half while inside-out, which minimizes wrinkling and helps protect the outer layer of the jacket (Ms. Settie shared instructions here). Or simply wear your blazer onto the plane, something Ms. Settie suggests because jackets and jeans take up a lot of space and weigh more. Besides, she said, doing so gives you “the added benefit of traveling in style.”

As you place items in your bag, think about balance. Put heavier items, like shoes, at the bottom (near the wheels, if your bag has them). Ms. Frommer said she typically packs two pairs and stashes things such as socks and jewelry in them.

Clothing should go toward the top of your bag to reduce creases created from weight, with jackets going in last, Ms. Settie said. You can also add a layer of protection from wrinkles by putting skirts and blouses in plastic dry cleaning bags before folding them flat and then placing them at the top of your bag.

Borrow and buy

A bit of research ahead of time can free up a lot of room. Call your hotel or vacation rental to find out if items like hair dryers and sunscreen are provided so you don’t have to pack your own, and ask if they have washing machines or offer cleaning at reasonable prices.

And don’t worry about packing for every possible eventuality. Buying practical things while you’re away can be great fun. It’s an opportunity to talk with locals, try regional products (like the affordable beauty elixirs found in Parisian pharmacies) and, of course, bring a few treasures home, thanks to all that room that’s left in your bag.

Many people experience the morning altitude headache, in which “your skull feels too small for the pulse that’s coming,” said Steve House, the founder of Uphill Athlete, a company that offers high-altitude endurance coaching.

It is also common to struggle with sleep at high altitudes. This occurs partly because the part of your nervous system responsible for keeping you awake has kicked in to increase your respiratory rate, Mr. Nicolazzo said.

Pay attention to elevation

The two main drivers of A.M.S. are how high you’re going and how fast you’re getting there. People with a higher altitude sensitivity might start experiencing challenges not far above 5,000 feet, say in places like Denver and Johannesburg. Anyone traveling above 8,000 feet may be at risk for altitude sickness, according to the Centers for Disease Control and Prevention.

Serious adventure travelers — say, those trekking in the Himalayas, or climbing Mount Kilimanjaro — usually know they’re headed for high altitudes. But the elevation of destinations like Mexico City (about 8,000 feet), the summit of Haleakala on Maui (10,023 feet), Cuzco (about 11,150 feet), or even Santa Fe, N.M. (6,996 feet), might come as a surprise. To set expectations, check your destination’s altitude in advance on Google Earth or the U.S. Geological Survey national map viewer.

Listen to your body

If you have a condition like heart disease, heart failure, high blood pressure, high cholesterol, atrial fibrillation, lung disease, C.O.P.D., asthma or sleep apnea, you’ll want to start paying close attention to how you’re feeling at around 5,000 feet.

If you have a pre-existing condition or have had trouble with high altitudes before — or if you’ll be going above 10,000 feet — consider visiting a specialist, who can help you prepare and may be able to advise you about the main drugs used to prevent and treat altitude sickness, Diamox (acetazolamide) and dexamethasone.

Sleep your way up

Traveling to high altitudes is a little like running a marathon: It will go better if you build up to it.

Say you’re headed to a high-altitude ski resort. Consider working your way up from a lower sleeping elevation to a higher one, since the critical factor — for altitude purposes — is where you spend the night.

If you’re traveling from sea level to Breckenridge, a Colorado ski town that sits at about 9,600 feet, first spend a night in Denver, at 5,280 feet, advised Dr. Peter Hackett, the founder of the Denali Medical Research Project and a high-altitude specialist. By doing so, he explained, “you drop the incidence of headache by almost half. So that little bit of extra time that you take to get to 9,000 feet to sleep can make a big difference.”

Skip that fatty steak

When Mr. Nicolazzo worked as a ski patroller, there was a behavior so common — and certain to exacerbate altitude illness — he remembers that local lodges posted warnings about it. People would fly in from sea level, he recalled, drive to the ski areas around Taos, N.M. (which is itself at 6,969 feet), “have a big steak, baked potato with sour cream and a lot of butter,” along with several cocktails. Then, they would feel terrible the next day, he said.

To avoid that feeling, trade the steak and extra butter for something with more carbohydrates, as fats and proteins take more oxygen for your body to metabolize.

And if you’re having a cocktail, keep it to one: Alcohol and other depressants can decrease your oxygen level, particularly while you’re sleeping, Dr. Hackett said.

Above all, drink plenty of water. Staying hydrated will help your kidneys work better, Mr. Nicolazzo explained, which can help you adjust to the altitude and, hopefully, avoid the headache.

Watch for red flags

A mild case of A.M.S. can become moderate or severe if someone ascends too high or too fast. Most — but not all — people progress through the mild symptoms before reaching this level, which includes symptoms like dizziness, disorientation, severe nausea and extreme shortness of breath.

To guard against severe A.M.S., monitor how you feel, and if you’re experiencing a persistent headache, trouble sleeping or other A.M.S. symptoms, tell your companions and don’t ascend any higher.

At the severe end of the continuum, if not treated, A.M.S. could progress into high altitude pulmonary edema, in which fluid builds up in the lungs, or more rarely, high altitude cerebral edema, where fluid builds up in the brain. Both conditions can be fatal.

“There are three cures for altitude illness,” Mr. House said, “descent, descent and descent.” Anyone who appears confused, is coughing up fluid or seems to have trouble breathing or walking — symptoms of severe conditions like HAPE or HACE — needs to be taken down immediately, Dr. Hackett said. “Just a thousand feet is all they have to go. And that could save their life.”