Hi Ann, the first time I went on a long haul flight I did suffer a bit, but not really since. In fact, I've just returned from Vietnam and Cambodia, which took 36 hours continuous travelling! I live in south-east Ireland, so had further to travel than most. However, after three flights and two lengthy stopovers (eight hours in Kuala Lumpur airport!), I was still fresh enough for the three hour drive home from Belfast to Wexford. I don't have any magic solutions, but this is what I do:
Before the holiday, I get a couple of early nights so I'm well rested before the holiday begins (even if work has been hectic, I try to organise myself so there is no last minute panic and I start to pack a couple of days before I leave).
Whilst on the plane, I watch a film and have a couple of glasses of wine and try to get as comfy as possible and sleep as much as I'm able (same on the way back).
As soon as I'm aboard the plane, I change my watch to the new time zone (same on the way back).
Once there, I just adapt to the new time and go to bed at a normal time. Especially on the first few days of the holiday, and again on the last few days, I make sure I don't have any late nights. When I get home I do the same and eat, sleep etc at the normal times - so basically all I'm saying is, just try to rest on the journey when you get the chance and "ignore" the time changes by doing what is appropriate to whatever time zone you're in. Over the last couple of years, I've travelled long haul to north and south America, Africa and Asia and have not had any serious problems.
Hope this helps!
Bob