zagorfly, in over 24 years of flying longhaul, I can't say I ever found the various ideas of managing flying worked. If you are working, you are automatically going to have to fly over some or all of your natural sleep period. You will be VERY tired at some stage, whatever you do. Try and do simple things:
*relax and sleep before the flight if you can
*can you get a little sleep during the flight? No more than 30 minutes eyes closed to stop you entering a deep sleep which can make you feel worse.
*if you have a rest break, save sleep for then, and try not to waste it
*when you are on the trip, sleep when you are tired- don't get upset if you can't sleep, it doesn't help
*keep alcohol in moderation, it doesn't help
*sleeping pills have more of a delayed effect than you realise, better avoid them. NEVER take the strong sleeping pills. Better to avoid them altogether.
The repowering effects of a short sleep (less than 30 minutes) are wonderful.
Many times I would be flogging my way from London to Hong Kong, tired as I've ever been, promising myself when I got to a cool bed I would stay there for a week, only to find 30 minutes after arrival at the hotel I was in the Dickens bar ready for a night out! Just relax, take it easy, enjoy the trip, sleep when you can, no drugs and easy on alcohol.