When I was medicated, I didn't touch the stuff. Learned pretty quickly that you get drunk much faster and on much less while pumped full of psych meds.
Now while I'm unmedicated, well in general I drink when I want to, which isn't very often at all. For example, on Christmas I had maybe 4 glasses of wine, and before that was in October on my brothers birthday, when I had shots and a few whiskeys...
My rule of thumb is this though: Check and recheck my mood before ingesting ANY alcohol as it amplifies and magnifies my mood tenfold.
So absolutely NO sad or depro drinking allowed. Ever.
I get drunk on purpose, maybe once a year, (usually NYE) and that's because I generally loathe relinquishing any kind of control, so I commit to doing this "let loose, really loose" thing annually. Although truth be told I don't even stick to my annual rule.