Go to a supermarket.
Time your entrance into the store such that someone else triggers the door to open -- so that if you had never existed the door would still have opened at that moment.
Walk up and down the aisles without touching anything. Then, to leave the store, time it so that someone else triggers the door to open.
If you should accidentally touch something -- a person, a shopping cart or a product -- select something cheap in the shop, buy it and leave through the checkout counter in the normal fashion.
Don't buy the thing you touch since it may be a person or a shopping cart or something incredibly expensive.
The intention is to not touch anything. If all goes well, you will have entered without causing the door to open, walked around the store without touching anything and left without causing the door to open.
Keep trying this until you complete it to your satisfaction. Should you wish you may send a copy of your journal report concerning the activity.