You probably already know the one surefire way to avoid a hangover. But if teetotalism isn't for you, Fred Freitag, D.O., assistant director of the Diamond Headache Clinic in Chicago, offers this game plan for having your cocktail and drinking it, too.

Before the party: Eat, preferably something high in fat. "That helps delay the absorption of the alcohol," explains Dr. Freitag.

At the party: Drink up...water, that is. "For every drink, have a glass of water," says Dr. Freitag. Alcohol, he points out, is a natural diuretic, so a long night of drinking can leave you dehydrated. By drinking water or juice in addition to alcoholic beverages, however, you'll minimize your chances of getting a hangover and even of getting intoxicated to some degree, he says.

Alcohol flushes the salt out of your body as well. To counter this, eat some salty foods while you're drinking, says Dr. Freitag. Besides the chips and pretzels, help yourself to the fruit bowl. Fructose, the sugar derived from fruit and honey, is used by the liver to metabolize alcohol. (Juice is not a satisfactory substitute, though, because it's often sweetened with plain sugar rather than fructose.)

Despite the common myth, drinking more than one kind of alcohol in one night won't cause you to become drunker or more hung over, says Dr. Freitag. Also, unless you're among the 10 percent of the population who always gets a headache from certain specific alcoholic beverages, one type of alcohol isn't any more or less likely to cause hangovers than any other kind.

Before bed: Before you pass out—er, go to bed, be sure to: 1) Drink some extra fluids; 2) Eat something salty; 3) Eat a piece of fruit; 4) Take aspirin, ibuprofen (Advil), or naproxen sodium (Aleve), says Dr. Freitag.

In the A.M.: "The worst thing you can do," says Dr. Freitag, "is the hair-of-the-dog routine." So skip the Bloody Mary and instead have a strong cup of coffee, a cola, or another caffeinated beverage, which has a constricting effect on those dilated blood vessels. A couple of aspirin or ibuprofen, a multivitamin to replenish the B vitamins flushed out by the alcohol (which are necessary for metabolizing alcohol), and a lot of water are also helpful. Avoid a high-fat breakfast, which can irritate your stomach; instead, eat a light meal consisting mostly of carbohydrates, such as toast or cereal. And unless you're really motivated, don't bother to exercise: It won't help your body work the alcohol out of your system any faster than lying on the couch watching cartoons.