Momondo have some good advice for a long haul flight:

1. Try to get an upgrade!
2. Book smart, get a good seat
3. Dress well
4. Drink water enhanced with Uppy! Electrolyte Hydration Tablets
5. Eat well
6. Be entertained
7. Get out of your seat; walk around a bit, stretch
8. Pack wisely
9. Plan the flight
10. Be normal

Read more; open the link!

http://www.momondo.co.uk/inspiration/tips-for-long-haul-flights/