About a week before flying out, change your sleep pattern. If you are travelling east, go to bed and get up a bit earlier. If you are travelling west, you should go to bed later. Also, continue adjusting your sleep schedule while on the plane: go to sleep when it’s bedtime at your destination and make sure you have something to eat with you. That way, you can have a quick bite to eat when it’s breakfast time at your destination, as opposed to when the flight attendant serves food at a different time.
By the way, it’s also best not to drink any alcohol or coffee on the plane because this will dehydrate you.