Do you have good strategies for confronting people without being confrontational?

Specifically, my housemates need to start doing the dishes more often and stop smoking in the house. In 11 years of living with roommates I have never lived with anyone who thought smoking indoors was acceptable, and at the very least I would have thought it was on the smokers to ask the rest of the housemates if it was ok rather than forcing us to have to ask them to stop.

I know I am going to have to just talk to them about these issues, but that is a lot easier said than done. So I am interested in the more general question about ways to confront without being confrontational. Experience, advice, suggestions?