"Mix" being the operative word!! Sleep/don't sleep/drink/don't drink and so on.

The best advice I can give is not to fret about jetlag. If you feel tired on the flight, get an hour or two of sleep - if you're not tired then don't try to force yourself.

If you do drink alcohol, try to alternate this with water. Have a shower upon arrival at your hotel, go for a walk and you should be ok.

Try to wear loose fitting clothes on the flight.

The key in my view is mental attitude - do not under any circumstances keep thinking about UK time - change your watch on boarding to PST and stay on it. Don't think about jet lag; don't race around and just try to relax. If you do that, I'm sure you'll be fine!