The food thing. Everyone knows this already. Eat something before and during alcohol consumption. This slows the absorption of alcohol. Fats and carbohydrates are best for slowing absorption.
Sugars intake prevents hang-overs.
Cakes and pastries are the party food that has lots of all three. The water thing. Dehydration is a big part of hang-overs. Combat it while you are drinking. Intersperse the measily ration of drinks a woman has, with water-based drinks.