Have a friend who wanted me to ask:

He plays three handed poker with guys a couple of times a week on lunch break. He wants to know some basic strategy for beating this game consistently. My theory on games like this is that it's largely a crap shoot but he has the ability to get amazing reads on these guys because they will play the exact same every time (because they are probably that dumb). I told him that:

Mix his play up constantly so that they cannot get a good read on HIM. Bet differently sometimes, raise differently sometimes, limp sometimes. Never do the same thing day to day.
Lower minimum hand requirements because basically they are going to see every flop every time unless you have a read that one of them has a decent hand and you have crap - most of the game will be won post flop.
Make them pay for drawing hands - I took him apart a couple of times because he would try to draw out everything and I would take all of his money when he didn't hit. The couple of times he did hit didn't make up for all of the times he lost trying to hit a flush/straight.
Don't be afraid to fold PF and let the other two battle it out - if one knocks the other out then you're heads up and better off than you were.

Anything else? I also told him that the goal would be to consistently play well, no matter what happens - because in a three handed game luck is a huge factor. Don't play based on pride and remember each hand is independent. He had trouble getting his head around that.