For long haul international, I try to book flights (lie flat seat only) that have me flying during my normal sleep time. Ex-West Coast to Europe (10 or 11 hours flight) with an 8.30pm departure for example. (I try to avoid the more common flights that leave in the afternoon, because sleeping from say 8 or 9 pm to 4 in the morning doesn't work for me at all. I'll just get at most 3 or 4 hours fitful rest).
Around 10.30 or 11.00, I'll take a Melatonin or two Tylenol PM tabs and read myself to sleep.
On good flights, I'll sleep 7 or 8 uninterrupted hours, waking fully rested at what my body thinks is early morning but is usually late afternoon on the clocks at my destination.
Really, it's that first post-flight night (which will seem to my body to be only the afternoon) that must be slept through to get past jet lag.