I also tend to start eating lots of small snacks all day, rather than sitting for 2 or 3 big meals. This gets my body in a rhythm of evenly working metabolism. Continue this pattern on the plane, and when you get there, and you'll have less of the ups and downs of energy we're used to in everyday life (i.e., feeling sleepy in the afternoon after a big lunch, etc.). It allows your body to adjust to the new time zone more easily, because the body has less to reset.

I agree HIGHLY with the H2O requirement. I bring one of those big 1.5 litre bottles of water with me and usually drink the whole thing on the flight, a bit at a time. This keeps me from having to ask the waitress AGAIN for more water every hour, and I don't have to wait till she can get back to me.