Hydration the night before and anytime you wake up during the night usually seems to do the trick for me. Even if I'm wasted, I force myself to down a glass of water or two before going to sleep. Anytime I haven't, I've felt horrible the next morning.
I used to always go to McDonalds after a crazy night, but I got over it because I would eat tons of stuff that I wouldn't remember eating the next day, and I gained mad weight because of it. To my friends I'd be like 'Hmm.. I think I'm gaining weight, but I don't know why', and they'd be like, 'It's because you ate 40 chicken Mcnuggets, a Big Mac, and a strawberry milkshake last night'. lol. So I made myself stop.
But I've found that if I don't eat anything the night of drinking or the next morning, then I'm not as sick. And if I still have a hangover, a really hot beer works magic. I usually heat it up over the stove until it's boiling and then I sip on it like tea.