Sweeties and a good meal before you go out is definitely important. As much water as you can manage before you go to bed. Headache the next day is mainly dehydration and as well as counteracting that with water you need potassium. Fresh orange juice or bananas are good sources.
I always eat a meal and drink a lot of water right before bed and I never get hangovers no matter how much I drink. You just have to make yourself do it. you'll thank yourself in the morning