Drink lots of fruit juice and water now, before you start drinking alcohol. Drinking these beverages now will have more affect than twice the number of the same beverages in the morning.
 
Other than avoiding alcohol, there are some sensible things you can do do lessen the severity of your hangover symptoms. Avoiding a hangover or at least diminishing the affects of it can be done in 3 stages. The 3 stages are the “Before you drink”, “During the drinking” and “After you’ve had your fun with Alcohol”.

Before You Drink:
There are a few things you can do before you start drinking that may help to either avoid or lessen the hangover symptoms.

Eat a healthy meal that includes starches and essential vitamins and minerals, especially B vitamins. Food will absorb the alcohol you consume and lessen the affects of the alcohol. Greasy food may not mix well with alcohol, so a burger or pizza may not be a good choice. Eating greasy food, and then drinking alcohol and carbonated drinks and you will end up courting the porcelain queen.

Drink lots of fruit juice and water now, before you start drinking alcohol. Drinking these beverages now will have more affect than twice the number of the same beverages in the morning.

Get your favorite hangover remedies ready before you go out drinking. This preparation the night before will save you from having to open cans and jars, mixing, stirring or finding things in the morning when you will more than likely not want to be doing these things.

Drink prickly pear fruit extract several hours before you start drinking and you will reduce your hangover symptoms. You can take a trip to your local drugstore and purchase one of the many anti-hangover remedies they sell.
 
While You Are Drinking:
In between alcoholic drinks, drink a glass of water or a glass of fruit juice.

Do mix food with alcohol. Eating or at least nibbling on snack food will help absorb the alcohol that you are consuming. The sooner the alcohol is out of your system the fewer hangover symptoms you will have to endure. Peanuts, and popcorn will do nicely as well as raw veggies, crackers or sandwiches.

Alcoholic drinks that are darker in color contain more congeners and will give you bigger headaches. Lighter colored alcoholic drinks like white wine and vodka will give you fewer headaches. Just remember that dark is bad and light is good. Stay away from the cheap stuff as it can give you more headaches. Stick with light colored, quality alcoholic beverages to reduce your hangover symptoms.

To avoid the larger degree of pain, remember this handy rhyme: “Liquor before beer, never fear, but beer before liquor, never sicker!”

Time your drinking - consume less than one drink each hour. This will give your liver time to break down the alcoholic content of the drinks. If you spread out your drinking over several hours and drink less than one drink each hour, you will give your body a chance to keep up with your alcohol intake and feel less affects the next morning.

After You Drink:
Once home for the night and your drinking is done there are several things to do to help you lessen the affects of what you were drinking.

Immediately upon getting home, drink one tall glass of plain water. Take a vitamin B supplement if you have it on hand (probably a good thing to stock up on if you drink often).

Warning:
If you did happen to overdo the drinking and you notice any tremors, stomach pain, or see blood in your vomit you should visit a doctor.