BEFORE YOU DRINK:
Eat: Eat something that has vitamin B and C such as fruit. If you are going to an after hour party, you should eat early dinner before you go to the party or eat while you drink. The fructose in foods will help absorb alcohol.
Vitamins B & C: Take vitamins B & C. Alcohol will deplete nutrients from your body and the vitamins will help you replace what you lose from your body by drinking. Drinking orange juice, grapefruit juice, and grape juice will also help.
Drink Milk: Milk will help absorb alcohol slowly.
Know Your Body: If you had hangovers before, learn from your experience. Were you drinking dark liquor? Were you drinking different types of liquor all night? Were you drinking too fast? Try to analyze what your body can handle. Dark liquors (or colourless liquors) make some people feel sick. Some say drinking different types of liquors or liqueurs bring them headaches. However what you drink doesn't matter as much as how much you drink.
Do Not Drive: Do not drive a car to get to where you will be drinking unless you have somebody who can drive you back.
WHILE YOU DRINK:
Drink Water: always order a cup of water when ordering an alcohol beverage. Water will help rehydrate your system. The more water you drink, the better solution after the night.
Eat while you drink: Try to eat while you drink if possible. Food will not only help absorb alcohol slowly, but also slow your drinking pitch down.
Order fruit cocktails: Fresh fruit juice will replace the vitamins that you lose from your body while drinking. If you know that you are not a big drinker, try cocktails with simple ingredients such as Rum and Orange Juice or Vodka and Cranberry Juice etc.
Watch Your Pace: Never drink too fast. Drink as slow as possible. When you feel fine (meaning when you can tell or cannot tell that alcohol starts changing your behavior, thinking, and sight etc.), you should stop drinking alcohol and drink water. If the party goes longer than you expected, order some fruit juice.
Drink Water: before going to bed, drink water. Do not drink coffee. Coffee will help dehydration.
Vitamins B & C: Take some vitamins before going to bed.
Sleep: sleeping may be difficult because your body temperature is higher than usual. If you can't go to sleep, drink more water. If you need to throw up, throw up. When you wake up, drink more water and eat some fruits and try to go back to sleep.
Despite all the things that you could do to avoid a hangover before you drink and as you drink, if you still get a hangover, you are not trying enough. Think about what went wrong and learn from your experience. And remember, drinking is supposed to be fun! Not to throw up at the end of the night.