Short flights are easy. Anything under three hours and you're barely on the plane; if you're lucky, you'll have time to watch a movie. Three- to six-hour flights are straightforward. Between a meal or two, a movie, some work, and a nap, time flies. But long-haul flights… Long-haul flights are a different beast. At best, eight hours is like a work day; at worst, 14 or 15 hours (or more!) is a day of your life, a day in which you'd normally be exercising, interacting with people, working, cooking, dining out, sleeping.

It's tempting to block out the sheer length of a truly long flight until it's actually underway, but that's a mistake. You'll find yourself bored and uncomfortable by hour six or seven, glaring at the flight tracking screen and unable to fathom how you'll survive the interminable abyss ahead of you. Instead, go into your flight with a plan, and you'll step off the plane wondering if the flight was really as long as expected. Here's what you need to do.

Clothes

First things first: What do you want to wear for a sedentary, day-long journey above the earth? Unless you're flying first class in Emirates, which includes showers, you're going to be wearing those clothes while sitting in a stuffy environment for a long time, so comfort and longevity are key. Linen and silk crease easily, while sweatpants and leggings look slovenly; stick with dark colors, layers, and tailored cottons in order to strike the right balance. Loose dresses are perfect for ladies. Bring a spare sweater to throw on at the end of your flight (if weather appropriate) in order to look a little bit fresher after a day in the sky.

Food*

Have you ever had your flight leave at 10 p.m. only to find the flight attendants are serving dinner an hour after takeoff? Meals in the air sometimes feel designed to confuse your body, especially because it will take longer to digest food when you're not moving around. Just remember: You don't have to eat it just because it's being served, and you can even bring your own food if you want to eat at different times. Figure out how you want to calibrate your internal clock based on your arrival time and work backwards from there. For example, if you're taking off at night, eat before you go to the airport and skip the plane dinner in order to sleep for the first few hours; rejoin the rest of the flight for breakfast. Which brings us to…

Sleep

Food and sleep are intertwined, especially on flights: It's hard to fall asleep right after eating even when you're not at 36,000 feet. So, again, figure out before you get on the flight when you want to sleep (or, try to sleep, if you're not taking a sleeping pill). Are you going to break up the trip with a several-hour nap? Will you try to sleep for the first several hours? Take into account what time of day you'll be arriving, as well as the time difference. Remember, too, just how depressing it can be to have watched several movies, slept for several hours, and then wake up only to realize that you're still only halfway through the flight. In other words: Multiple naps are allowed.

Movies (and other activities)

For most of us, the most logical strategy for getting through hours upon hours in a confined space seems to be to power through as many back-to-back movies as possible. It sounds good in theory, but after two or three movies in a row, the realization that you could watch four more and still not be at your destination can be morale-killing. Bring a book or two, some work (you know you've got some), a notebook, podcasts, and crossword puzzles to break up the movies so you don't burn out too early. Also, for better quality video, load movies or TV shows on your laptop or tablet before your trip; this also guarantees you'll get to watch things you're actually interested in.

Movement

Remembering to move may seem obvious, but, considering how rarely most people stand up during a five-hour flight, you'd be surprised how far into a long-haul trip you can get before realizing you haven't gotten out of your seat. While you're unlikely to actually get a blood clot (though we still wouldn't risk it), sitting for that many hours makes your feet swell and only adds to the cold of an already air-conditioned plane. Plus, after nine hours of sitting, you'll go a bit stir-crazy. Go for a walk in between movies, get water every hour or so from the flight attendants instead of having it brought to you, do some stretches as you wait in line for the bathroom, and make friends with the parents hanging out in the back. Any excuse to get up will help make the flight feel shorter.

*As tempting as it can be to take advantage of the free alcohol, especially if you're a nervous flyer, booze not only dehydrates you but also messes with your sleep — which isn't what you want when you're trying to get some rest on a long flight. Also, overdoing it on the alcohol when you still have 10 hours in the air can make for some seriously unpleasant hours in the bathroom. Stick to the water and solid food, and maybe treat yourself to one glass of wine several hours before you're planning to sleep.