Showering with the lights off.
And having my teeth fallen. I suffer from cavities, I don't even know why I have so many, I brush my teeth twice to thrice a day. :( so I'm seriously scared of ending toothless at some point.
Floss. I have some floss picks near my bed, computer and bathroom. I just idly use the floss picks a couple times throughout the day, usually watching YouTube or something and have only gotten 1 cavity despite going through really bad depression and poor dental hygiene.
I use floss, too. :( .every morning and night. I still don't know the reason for it. A dentist told me it was just a genetic thing and I should be way more careful than others. Another dentist told me it could probably be anemia. But I've read that bulimia causes cavities (I used to be bulimic for a long period)
Also, I ripped one of my own teeth out at 16. (I congenitally lack 4 permanent ones so the milk teeth they were supposed to replace never fell out. Had the last one taken out at 18.) The crunchies while wiggling the tooth was actually not unpleasant. Nostalgic, it was.
Also, we're doing pretty well for a drug which could regrow teeth, so you can worry less about ending toothless.