If you go to a matinée in a movie theater, where there are only a handful of individuals trying to eat their popcorn in peace, try not to sit next to another patron. Better yet, get your own row.
If you're at the gym, where there's a whole row of assorted cardio equipment, don't get on the elliptical trainer right next to someone. Branch out, give people their space. It's tough enough dragging my fat ass to the gym without having to share hot, sweaty air. Geez.