The type of trip you’re taking dictates how you pack, of course. The clothing and gear you’ll need depends on whether you’re headed to a beach resort, on a business trip, or to remote pockets of a developing nation. But there are certain items I pack every time, especially when an overnight flight is required to get there.  These are the must-have items I fit into one carry-on wheelie, plus one laptop-holding handbag.  Here’s what I find most useful.  How about you?

For the flight:

• Inflatable airline neck pillow. The Cocoon Ultra-light Air-Core Neck Pillow, for instance, weighs practically nothing and takes up no space.
• Inflatable lumbar support cushion. On long flights (as well as in uncomfortable wooden chairs at your destination), this Vive pillow can save your spine.  It folds into nothing in your carry-on.
• Eye mask, earplugs, hand sanitizer, sleeping pills, Vitamin C, and tiny vials of eye drops and hand cream. Place them in a sandwich-size zip-top bag, and you’ve created your own business-class amenity kit.
• Shawl, sweater, or travel blanket—for an extra layer of warmth on the plane (remember, it’s smart to turn on your overhead air nozzle, since it scatters viral particles, but it can also chill the air) and at your destination (where my pashmina shawl doubles as a headscarf in the rain, a picnic blanket, etc.)  For a more masculine style, think Cocoon Coolmax Travel Blanket.
• Headphone Y splitter. Parents, listen up: It connects two headphones to one jack, enabling two of you to use the same device (e.g., two kids can watch the same movie on one iPad).

At the destination:

• Sturdy, comfy walking shoes. Make sure they’re broken in.  In developing countries, favor black or brown (new white sneakers make it hard to blend in and are a dead giveaway that you’re a tourist).
• Ultra-light, compact jacket.  Mine happens to be this one—which I can even fold into its own pocket and use as an extra pillow on the plane—but there are many to choose among, from a windproof, water-resistant Patagonia Nano Puff to a Uniqlo Ultra Light Down.
• Ultra-light day pack. Throw it in your carry-on and use it when sightseeing and shopping. (If you plan to do a lot of shopping, here’s more packing advice).
• Crushable, non-wrinkle hat. I like Wallaroo hats because they’re UPF 50+.
• Smartphone that’s an all-in-one alarm clock, flashlight, map, and magnifying glass (use the camera zoom).  You can also use your smartphone camera to prevent these common travel headaches.
• Small binoculars or opera glasses (for when your smartphone camera zoom won’t cut it).
• Tiny but powerful flashlight.  For those times when your smartphone flashlight isn’t strong enough, carry a Maglite mini.
• Resistance bands for exercising in your hotel room.

To minimize bulk in your bag:

• 3 or 4 clear zip-top bags of different sizes—for holding liquid toiletries; wet bathing suits; or any other small items you want to organize and find easily. I place my liquid toiletries in one (for easy removal at airport security) and my dry toiletries in another. If you want to compress clothing (e.g., compress a wool sweater to half its size), try a two-gallon-size zip-top bag.
• 3 or 4 plastic bags they gave you at the grocery store. Like the zip-top bags, they weigh nothing and take up no space. I use these as shoe bags, and they can also hold laundry, protect a camera from rain, etc.
• 3 or 4 bags they gave you at the dry cleaner. I hang each item of wrinkle-able clothing on a separate disposable wire hanger, encased in a separate plastic dry-cleaner bag.  Then I hold all the hangers in one hand, fold the hanging clothes once, and place them on top of everything else packed in my carry-on wheelie, so that they lie smoothly across the top. This way, nothing ever wrinkles!
• Multi-purpose toiletries (e.g., facial moisturizer with SPF; shampoo-plus-conditioner that you can use as shaving cream) and liquid toiletries in disposable packets rather than bottles (e.g., makeup remover). Look here for possibilities.
• Travel-size detergent—e.g., Woolite packets or Tide singles for washing items in your hotel-room sink.
• Your oldest socks and torn underwear. Discard them as your trip nears its end, making room for souvenirs you pick up.

Troubleshooting:

• Extra camera battery and memory card. Don’t waste hours of precious vacation time searching for a store that carries these.
• Gaffer’s tape for on-the-fly, temporary repairs of shoes, bags, hems, and the like. (Alternatively, use a portion of the adhesive-paper bag tag that the airline affixed to your checked luggage.)
• Short 3-outlet extension cord that turns one electrical outlet into three, so you can easily charge all your devices in one spot at one time.
• Glasses you can’t lose. Clic readers mean you need not fumble through bags for your reading glasses.
• Kleenex packet. It can double as toilet paper.

Overseas:

• Adapter plug—for use in foreign electrical outlets.
• Photocopy of your passport (to keep in your hotel safe). Or snap a photo of the passport page with your smartphone (and email it to yourself in case the smartphone gets lost).
• Copy of your travel insurance or emergency medical insurance policy.
• Medical kit—including an antibiotic for respiratory ailments, an antibiotic for digestive ailments, acetaminophen, ibuprofen, antihistamine, antiseptic wipes, antibiotic ointment, Band-Aids, multi-vitamins. Just remember that medications need to meet TSA regulations and liquid ones must be 3.4 oz or less per container if they’re in your carry-on.
• Money belt or neck pouch. This pouch hides beneath your clothing. Don’t use a fanny pack; they attract pickpockets.
• Energy bars—for snacks when you’re not sure you can trust the food.
• A few photos or postcards from home—to give rural children in developing countries. They’re great conversation starters with the parents.