Mine is failry simple.

A lot of water. When you drink a lot the night before and if you have the faculties to do so, gulp as much water as you can before you go to bed.

Keep a huge glass at your bedisde and gulp if you wake up during the night.

Get more if you run out.

Drink a lot more in the morning, and take some asperin.

I can't take asperin on an empty stomach so i try to eat something, apple, piece of bread, crackers, whatever.

And just keep drinking water.

I think most hangovers are from being seriously dehydrated.