Smile. It confuses people who wish you to be unhappy.
Adam Rifkin stashed this in Smile!
I am a kind of paranoiac in reverse. I suspect people of plotting to make me happy. — J.D. Salinger
On the other hand, you shouldn't smile all the time, right?
If you do that, people wonder what you're thinking about.
Occasionally throw a smirk in there...
I don't like to smirk. I'd rather just go to neutral. :)