Bite your lip?
Unintentional Smirking

http://www.youtube.com/watch?v=NHydngA5C4E&ob=av3e
this is a cute music video, lol at around 1:30, don't smirk when you play madonna or she might flip the board.

I click my tongue when I'm thinking. Bad habit. Irritates the crapola out of (most) people.
As far as smirking, I'd say let it alone & just play like you, unless someone says something to you about it, or the other player seems irritated by it.
I do it (smirk) sometimes, but only typically if I'm expecting something to happen, or the other player does something unexpected and harsh that I didn't catch coming. (Appreciation of unique play, or humoring myself for not catching something obvious.)
The thing I've found most offputting since my return to OTB play is playing someone with poor personal hygiene. There seems to be a lot of it about

Post #14 of the guy playing poker is great! I attempt to have such a stance when playing chess OTB. Some people find that annoying. Well, I don't do that while playing skittles, but I have to remind myself to be more sociable during skittle games. Usually when I play chess my full attention is on the board - I'm in my own little-chess-world.
This might be a little weird.
For whatever reason, every time I play a game of chess, accompanying each move made by either me or my opponent, I can't help but smirk. It's the douchiest thing. It's not because of any real arrogance, or because I see some tactic, or what-have-you. Whether I'm taking the game seriously or just playing casually.
Just wondering, does anyone else do this? If so, have you figured out how to stop?