In my list of goals for this year, I have that I want to choose and develop a new habit or two each month. I think this is a great way for me/us to get into the habit of doing things that we should do but usually don't.
I know which one I want to work on right away :) I want both of us to get into the habit of taking our dirty dishes from the table to the sink or dishwasher when we're finished with the meal or snack. Usually we just let them sit and I clean them up the next day or whenever I get around to it. And it's annoying to have to go hunting down dirty dishes each time I run the dishwasher. Why haven't I done anything about it before? I don't know.
This might be more along the lines of creating and sticking to a new "house rule" but it's certainly something that if we do it often enough, we'll get into the habit of doing it.