About once a week on average. I may not drink anything for several weeks, and I may drink 2-3 times a week on occasion - usually around holidays or whatever. But I usually like to get lit up good about once a week.
When I do drink, I drink liquor - either a good vodka or Crown Royal mixed with diet soda. And I get tuned up pretty good - I either do it right, or don't do it at all.
If I'm drinking at home or at some BYOB event, my own drinks are mixed in a very large "Super Big Gulp" sized cup with lots of ice. One drink for me at home is about 4 oz of liquor to about a half a liter of diet soda. And I'll usually have at least 3 of these. Of course when drinking out at bars, restaurants, etc I have to settle for much smaller drinks.