You've gone through your pre-trip checklist, your suitcase is packed, and now all that's left is to pack your personal item. Long flight? We've got 15 items you don't want to leave behind.

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Reusable Water Bottle

Dehydration is the number one culprit on long flights for diminishing your health—it dries out your skin, makes you more susceptible to jet-lag, and weakens your immune system. This handy collapsible and foldable water bottle won't take up much space, and stows easily.

Don't Forget: You can save money by refilling the water bottle rather than buying bottled water—most airports have "hydration stations" scattered throughout terminals. Just make sure your bottle is empty before going through the security line.

Related: 10 Free Things You Can Get at Airports

Headphones

This one is important, especially on long flights as standard headphones (especially the free ones on planes) get uncomfortable when worn for an extended period. Make sure you pack headphones you know will be comfortable for binge-watching TV shows and that can help block out noise when you want some shut-eye. We recommend SleepPhones as a go-to for comfort and sleep on longer journeys.

Don't Forget: Make sure you download a relaxing sleep playlist and use an app like Spotify Premium, which lets you access your music offline.

Snacks

The type of food you eat during a flight will make or break your body's reaction to traveling longer distances. We recommend avoiding these eight foods and instead packing light snacks like nut mix, cheese and crackers, and fruits that are low in carbs and high in protein.

Don't Forget: Gum. It takes away bad breath after snacking and helps relieve ear pressure while taking off and landing.

Mini-Toiletry Bag

The following handy list of travel-sized necessities is great for any flight—with a few additions specific for red-eyes and long trips.

To keep your skin moisturized pack Mist Spray, Papaw Ointment, and a shea buttercream. For hygiene take a dry shampoo spray bottle, a disposable toothbrush, natural deodorant, and hand sanitizer. This slim portable travel toiletry case is perfect to keep everything organized.

Don't Forget: Medicine—it's always wise to keep your prescriptions in your carry-on, plus a few pain reliever tablets and anti-histamines in travel size containers.

Compression Gear

For any flight, compression clothing encourages good circulation and helps your body adjust to pressure changes; but it's especially important for longer flights. So, pick your go-to pair of leggings or socks.

Don't Forget: You'll want comfortable shoes to go with your compression socks for bathroom trips. Foldable slippers work well if you want to go shoe-free on the plane. Alternatively, tennis shoes or slip-on flats (like TOMS) are good options if you want shoes that go on and off easily.

Related: Do Compression Socks Really Work?

Scarf (That Doubles as a Blanket)

To avoid using the (sometimes) gross airplane blanket, wear a scarf—yes you will have to remove it to go through security, but you'll be grateful later when the plane's AC is blasting. This versatile option from Dimore can be worn in dozens of ways, making it a cozy choice for the plane and a smart packing choice for a variety of outfits.

Don't Forget: Make sure you dress comfortably overall—remember you're in these clothes for the long haul. If you're on a red-eye, keep in mind you may not be able to check into your hotel right away, so it's always a good idea to pack an extra set of clothes in your carry-on.

Sleep Aid

Everyone has their preferred method for falling asleep, but planes provide extra discomfort, making relaxation even more difficult. Melatonin spray or pills are good sources for over-the-counter, natural medicines to replace a prescription sleep aid. Other holistic remedies like Yogi Bedtime Tea bags or Natural Vitality Natural Calm also work wonders for relaxation.

Don't Forget: Throw in RMS "un cover up" to quickly energize and refresh skin before getting off the plane.

Paperback Book or Magazine

Bring at least one form of non-electronic entertainment for takeoff and landing, or any time you want a break from screens (or gasp, when your Kindle dies).

Don't Forget: Oftentimes magazines and books are more expensive in the airports, so BYO from home.

Back-Up Entertainment

The dreaded blank screen on your inflight entertainment—if it hasn't happened to you yet, consider yourself lucky. Just in case yours fails you (or if you just want your own entertainment), bring a laptop, tablet, or reader. Consider a compact back-up hard drive to store movies or TV shows to watch on a laptop.

Don't Forget: Pre-download any shows or movies on any subscription services you have that allow this feature, like Amazon Prime or iTunes. Also, charge all your devices the night before your flight, just in case your seat doesn't have outlets.

Jet-Lag Relief

These No-Jet-Lag pills are great for long flights and changing time zones. They are an all-natural New Zealand remedy to help regulate your body clock and alleviate body stress.

Don't Forget: Make sure to follow the instructions of taking one at take-off and then every two hours during your flight—it's worth waking up from your nap for.

Wipes

Don't be embarrassed by this one. Planes are covered with germs and are any easy environment to catch colds. Traveling with bleach wipes means you always have a way to sanitize your seat and surrounding area on the plane. But, that's not all wipes are useful for—La Fresh Travel Wipes Line offers an array of products, from nail polish remover to face cleansing wipes to bug spray. Wipes not only eliminate liquids in your carry-on, they free up space, and won't leak or spill in your bag.

Don't Forget: Check to make sure the wipes don't have an overwhelming smell before using them on the plane—it's tight quarters and you'll be sitting next to your seatmate for a while.

Related: The 10 Germiest Places You Encounter While Traveling

Eye Mask

Eye masks help create a more relaxing environment for sleep. They are also a good jet-lag remedy, as sleeping in darkness makes you better rested. Make sure to pick a pair that doesn't apply pressure around your head, like Dream Shields Sleeping Eye Mask Kit.

Don't Forget: This pair comes with ear plugs, but if you're relying on getting a full night's sleep on your flight, it's always good to bring an extra pair. You never know if that baby will be next to you …

Neck or Travel Pillow

Another way to increase comfort on planes is by using a neck or travel pillow. The J-Pillow offers unparalleled head and neck support for an easy sleep. Even though it's cumbersome to carry, the comfort is worth it.

Don't Forget: You do have to carry this around, so if you don't have much room left or don't want to be lugging extra items, look into an inflatable option or clothing with a built-in neck support feature.

Back-Up Power Charger

Even if you charge all your devices pre-flight, they will most likely die or have low battery by the end of your journey. Most larger planes now have power outlets at seats, but this is never a guarantee. This compact size portable charger won't take up a lot of space and gives a quick, full charge to your phone to make sure you have battery life when you land.

Don't Forget: This charges using a USB cord, so pack an extra USB output charger (and any necessary converters), because you'll want this at full battery for long tour days too.

Perfect-Sized Underseat Bag

Now, you're going to want someplace to put all your essentials that doesn't hog your leg room, fits a laptop, and still allows for easy access. The High Altitude Flight Bag is super slim and even attaches to the tray table in front of you. Or, opt for a slim backpack that can fit under your seat on its side—Cocoon backpacks offer an array of options.

Don't forget: A space pen. You'll most likely be going through customs if you're on a longer flight and will need to fill out various forms and documents. This pen can write in extreme temperatures, at any angle, and even at zero gravity (although you probably won't be needing that feature).

Read the original story: The 15 Items You Need to Survive a Long-Haul Flight by Ashley Rossi, who is a regular contributor to SmarterTravel.