There are rules for everything: driving, dating, and would you believe, drinking.
Having worked in various bars, I have a deep appreciation for these. Douche bags are bad enough, drunk douche bags are pure, liquid evil.
Two of the most important:
#28. If you can't afford to tip, you can't afford to drink in a bar. Go to the liquor store.
#50. Never brood in a dance bar. Never dance in a dive bar.
Read all 86 of these important drinking rules here before you head out for the night. Please.