Not a big fan of sleeping pills, so I usually do my best to make sure I'm ready to sleep ASAP when I get on board.
I normally eat about one hour to 30 mins before boarding and make sure I drink about half a glass of water before I fall asleep so I don't wake up parched.
I reset my watch to the time zone in which as soon as I take my seat, and then I pop in the earplugs and put on the eyemask as soon as we hit cruising altitude and hope for the best.
Even three hours of sleep makes a huge difference if you are landing in Europe at 6AM.