If you plan to spend your later years eating more than yogurt and applesauce, invest in some floss.
No matter how thoroughly or long you brush your teeth, you're missing a good portion of their total surface. That's like washing one armpit after a workout. But the dangers of skipping floss go beyond #hygiene: The bacteria that linger can increase your risk of heart disease. I use Reach Ultraclean floss, which stretches to glide between #teeth.