I too join the group warning about too much booze while flying. But when you are in a premium class seat, it is hard to turn down.

What has worked the best for me is to take a 25 mg Benadryl shortly after takeoff. I may have a cocktail and/or a glass or two of wine with the meal and after making a trip to the lav, I'm usually sleepy enough to nod off.

The length and quality of my sleep depends a lot on how much activity is going on with the other passengers. I'll put on my eyeshades and headphones, listen to ambient music and hopefully will try to get several hours.

I feel like I've done well if I can sleep 25 - 30 percent of the flight time.