Drink plenty of fluids to prevent dehydration it also helps in flushing toxins from the body. A hangover is caused by dehydration. As a prevention method, drinking a glass of water for every alcoholic beverage that you consume. This slows down drinking, and provides more time for the body to deal with the alcohol (the body can only process about three-quarters of an ounce of alcohol in an hour).
The morning after drinking.
Eating breakfast could help start your day. Just be sure your stomach can handle what your putting into it. We don't want to be throwing up what you just put in. Hair of the dog is just a myth and will just post pone your agony. Eating eggs breaks down the hangover-causing toxin in the liver and helps mop up the left-over toxins. Bananas help calm the stomach, Bananas are also rich in the important electrolytes, magnesium and potassium, which are severely depleted during heavy drinking, kiwi fruit or sports drinks help also. Remember to continue to drink water/Gatorade throughout the next day to get your body re-hydrated again! Get plenty of sleep.
The only true cure for a hangover is not to drink in excess or at all!