I carry a small canvas tote - easy to carry my water bottle, and I can put catalogs and literature in. No zipping and unzipping. Holds a couple of cars. More durable than plastic or paper bags. I'm always aware of it, so won't hit anyone with it. When it gets full, or I buy something large, I carry it back to the car.
The aisles are too crowded for wearing a backpack on one's back - it's rude. The only considerate way to carry a pack is on one's front; IMO, this makes it hard to see what's on the table, and increases the risk of knocking something off. People tend to get lost in the excitement of all the interesting stuff and lose their self awareness.
Please leave the backpack in the car.
