When I play live I will have a few pints before so I am more confident when sitting at the table. I always have this misplaced belief that live games are full of really good players. I play at 1/2 and its just full of gamblers/nits and maybe once in a blue moon a good player.
I somtimes have a drink at home on a Saturday night at home (2 at most) and then play, pretty much makes no difference.
However, one time I went out and had a huge night with a mate of mine. I got home and started playing heads up sng, a game which I am really bad at. I kept losing and buying in to higher games. I ended up registering for a £100 buy in game. I was waiting for somebody to join but fell asleep. I woke up a couple of hours later having missed the game. Moral of the story if you are planning a big night out do not turn on your computer when you get home.