Lots of liquid (esp. water, orange juice and tomato juice.) and rest...
But the best cure is Quit Drinking! Drinking can cause and lead to severe health problems like: Cancer of the Liver, Kidney Diseases, and countless other illness. If you've noticed na sakit kaayo imong ulo if you have a hangover because na-dehydrated imong lawas. You don't believe me? Try applying Vodka, Gin or Tequilla in your hands (or any exposed body area) and obsrve the drying effects afterwards...How much MORE if Alchohol is inside your body?