The first is not to drink too much. Stay away from shooters and mixed drinks. Second, pick the higher-quality choice. Drink water as you go. If you drink different concoctions over the course of your evening, expect to get a wider spectrum of undesirable stuff for your body to contend with.
White wines are generally safer than reds, but a good red is better than a cheap white.
Always dilute liquor with water or fruit juice. Carbonated mixers release gas, which forces uptake of alcohol at a faster rate. Avoid caffeine, as it increases the amount of alcohol and fusel oil you absorb. Finally, take a multi-vitamin and drink as much water as possible before going to bed.