1. Find a public restroom. Ideally in a restaurant, night club, or Apple store.
2. Grab all of the paper towels, toilet paper, and soap dispensers.
3. Stand near the exit, which is usually the same as the entrance.
4. If you are dressed like a butler, or wearing a tuxedo, this might work better.
5. When someone enters the restroom and needs one of the items that you've snagged, offer it to them for a low price, such as 35 cents. Or give it to them but act like you expect a tip. I'm sure you've encountered people who have expected tips from you before, so you should know what to do.
6. To enhance your money making opportunity, have some other items ready to offer your "clients", such as warm towels, hand sanitizer, or gummy worms.
7. If someone gets angry at you for hoarding the toilet paper, flee. Find another restroon and start over.