Besides the obvious of don't get wasted? Drink some Gatorade and take an aspirin. Also next time drink a bottle of water before going to sleep. Most of what causes the headache after drinking is being dehydrated. I have also found eating something a little greasy helps. I would always hit up my favorite sandwich shop the day after a night of drinking and get a hot ham and cheese sandwich with fries. I always felt better afterwards.
But that could have just been because they made the hot ham and cheese sandwich ever!
