1.  Fly with a decent airline.

Katie booked with Virgin from London Gatwick to Orlando, and was lucky enough to have basically the entire cabin to herself.
I on the otherhand, nervous about flying for 22 hours in the first place, booked with Qantas and United airlines, and both were outstanding.
Both of our international flights were on massive, unbelievably stable planes, which felt safe even if there was a little turbulence.

2.  Take comfortable clothes.

Katie has a routine of changing into her pyjamas for most long-distance flights.  She also recommends taking a shall or blanket with you in case it’s chilly on board – the ones provided by the airline are generally scratchy and horrible.
I prefer to simply wear a comfortable pair of jeans and a light sweater.

3.  If you can, put in a food preference.

On my Qantas flight, you could log in online prior to your departure and select a food plan preference.  The idea of a 10 hour old omelette for breakfast doesn’t interest me, so I chose ‘Vegetarian Oriental’ – neither of which I am…
It did mean that for breakfast I was served a vegetable noodle dish, but the vegetables were in a lot better shape than the gentleman’s eggs next to me.
Katie’s food advice is to take snacks on the plane with you.  There is nothing worse than sitting there for hours on end hungry.

4.  Pack a light-weight towel into your carry-on luggage.

Most airports these days have showers in their arrival gates where you can freshen up in between connecting flights.  It’s surprising how much better you will feel after a quick wash, or even just washing your face and brushing your teeth.

5.  Two words:  Sleeping tablets.