Eat before and during drinking; drink beer after liquor, not the other way around; dehydration is the villain; drink at least three glasses of water during the festivities; drink at least a liter of Gatorade before you go to bed; keep more water bedside so when you wake up in the middle of the night to piss, drink more; crash at your house or in an afternoon check-out hotel so you don't have to get up in the morning and drag yourself home; also, try not to drink very cheap booze, stick to quality.