For me, the flights were horrible. I could not really sleep, other than VERY short dozing, and I felt horrible when I arrived.
You might try some melatonin.
Dose up on your vitamins before departure; no telling what came aboard with the other 150 passengers (or the previous herds before them). I just spent a mere 4 hours trapped in a munchkin-sized seat in an aluminum tube with wings, and immediately contracted a rampaging case of MRSA or bird flu or something. Talk about feeling horrible; I'd have to get better to die.
If you're reading this, you may even want to disinfect your screen...