At one point in time, flying was a luxury experience. These days, with more fuel-efficient airplanes leading to longer flying times, traveling by plane can sometimes be more akin to a chore. Luckily, you can do a lot to be more comfortable.
Water is better than alcohol or caffeine. Finding a balance between taking care of yourself and allowing yourself creature comforts can be difficult. Water, however, will never betray you.
Bring Noise-Cancelling Headphones or Earbuds
You don't need to pay Dr. Dre money for a pair of Beats. (In fact, please don't; there are many better pairs of headphones out there.) Take a portion of the money you save by not being trendy and put it into something that cancels out noise. Even if you don't have music running the whole time, you'll be amazed at what a difference it makes.
Be Prepared to Sleep
Not everyone can sleep on a plane, but if you're on a 15-hour flight to cross an ocean, odds are you'll doze off at some point. Be comfortable. Noise-cancelling headphones or earplugs can stave off much of the ambient noise. Sleep masks, neck pillows, and picking a seat by the window can all help, as well. Honestly, the less time you spend conscious, the better.
Bring Lots of Entertainment
Whatever electronic devices you may rely on for entertainment, bring all of them, and make sure they're charged. Video game systems, phone, tablet, laptop. Whatever you have, bring all of it. And for the love of all that's holy, pick something with actual onboard storage because you can't count on a plane to have Wi-Fi. Don't forget, too, that books exist. They don't run out of batteries though they can be harder to focus on when your brain is fried after a day of travel. Choose something lengthy enough to last the whole flight, like the entire Harry Potter series.
You're not going to feel spectacular about being on this plane, but you know what? Neither is anyone else. No one wants to be here, from the flight attendants to the guy who keeps falling asleep and slumping over onto your shoulder. If you can bear that in mind and treat people accordingly, everyone's going to have an easier time.
This is going to be a rough situation, sure. But there's no reason to make it rougher. If you've shelled out for a trip like this, you may be feeling tight on cash, but give yourself permission to spend a little money in exchange for comfort. If the plane gives you the option to pay for in-flight Wi-Fi, and you want to use it, then go for it! If you feel like you could use a drink, let yourself have one. (Though bear in mind that water will be better for you in the long-term). Of course, you want to save some spending money for the destination, but you also want to make sure that when you arrive, you're not so exhausted and miserable that you can't enjoy your vacation.