Flossing! I floss frequently. I floss more than I brush my teeth (yuck) but it works. Logic behind the lack of brushing is that in the morning I'm drinking coffee and running out the door. At night, sometimes I fall asleep before I brush. But I have floss on my desk at work and in my coffee table at home (as well as obviously in the bathroom with my toothbrush). My dentist can't even tell I miss brushing at times. But can definitely tell I floss regularly.

You don't have to floss all your teeth, just the ones you want to keep.