Commercial flights aren’t known for their comfort — especially if you're flying in economy class.

And if you're on a long-haul flight (six to 12 hours) or an ultra long-haul flight (greater than 12 hours), comfort is even more important.

While you can't do anything about those shrinking airplane seats, there are several tips and tricks that can make those lengthy flights more bearable.

Choose your seat wisely

Travel writer Mark Hodson recommends using Seat Guru to find the most comfortable airline seating.

He also says sitting as far forward as possible can reduce noise, and avoiding the rows surrounding bulkhead seats can be beneficial since families with children are often seated there.

Generally, aisle seats are your best bet for comfort because they allow more room for stretching and give you easier access to the aisle and bathroom.

If you're on an airplane with a three-row configuration, the best seats are the aisles of the middle row because they give the people in the middle two options to reach the aisle.

While window seats can have great views, they've been linked to deep vein thrombosis because people in these seats are often less likely to get up and move around because they don't want to disturb their seatmates.

Pack smart

overpacked red suitcase Bringing too much stuff on the plane can mean less legroom if you can't fit everything into the overhead bin. (Photo: Africa Studio/Shutterstock)

While checked-baggage fees might encourage you to bring more stuff on the plane, keep in mind this often means less legroom.

To ensure you have as much space as possible, put your carry-on bag in the overhead compartment and tuck a few items you'll use during the flight — books, headphones, etc. — into the seat-pocket.

Be sure to pack an in-flight toiletry case with basic items like a toothbrush, hand sanitizer, medicine and anything else that will make your flight more comfortable.

Other items not to forget: ear plugs, an eye mask, a neck pillow and noise-cancelling headphones.

Also, bring books, movies, music and anything else that will help you pass those long hours in the air.

Finally, dress comfortably and be sure to layer.

Stay healthy

Plane cabins are dry environments, so it's important to stay hydrated. Skip the alcohol and caffeinated beverages, and drink plenty of water, even if you don't feel thirsty.

Keep in mind that airline food is high in sodium because it's more difficult to taste most foods at 30,000 feet, and all that salt can further dehydrate you.

While you might have heard that breathing planes' recycled air can expose you to bugs, you're actually more likely to get sick from touching your armrests, seatbelt, tray table or in-flight magazine, so it's a good idea to wipe down these surfaces with sanitizing wipes.

You're going to be sitting for hours on end, so be sure to stretch often and get up from your seat and walk a bit to improve circulation.

When to sleep

woman sleeping on airplane Getting too much sleep can throw off your body clock. Sleep when the cabin crew dims the lights. (Photo: Anze Bizjan/Shutterstock)

To get a good idea of when you should be sleeping, change the time settings on your phone or computer to that of your destination. Also, pay attention to the cabin crew, who often give visual clues by dimming the lights.

It can be tempting to pass the hours by sleeping, but keep in mind that getting too much shut-eye can throw off your internal clock.

If you plan to take a sleeping aid, test it beforehand. You don't want to have an adverse reaction while you're in the air.

Finally, listen to your body. If your eyelids start dropping, take a nap — but don't stress if you can't fall asleep.

How to sleep

Obviously, a seat in first class that allows you to lie back further will help you sleep better. But what if you're flying economy? Aircraft seating and interiors designer Adam White, director of Factorydesign, London, recently gave Travel + Leisure some tips on sleeping as comfortably as possible no matter where you're sitting.

“First get comfortable temperature-wise. That may mean standing up with your blanket and wrapping it around you and then put on your seat belt so that the crew can see that you’re strapped in,” he said. “That way the flight crew won’t find a need to wake you if the seatbelt light goes on.”

He also recommends wearing noise-canceling headphones and adjusting the light when possible to improve conditions for sleeping.

The best time to use the bathroom

To ensure a clean restroom and minimal wait time, Lifehacker suggests using the bathroom just after flight attendants have served food and moved out of the aisle.

While it can be cumbersome to move your tray table and maneuver yourself around other dining passengers, this is the ideal time because passengers are occupied with their food.

Just after flight attendants collect meal trays is often the busiest time for airplane bathrooms.

Editor's note: This story has been updated since it was originally published in August 2014.