Usually the cashier has one she'll swipe, or the customer following you in line is happy to get whatever "points" or whatever they accrue with the purchase. Or get one, give them all fake information and make sure you NEVER NEVER pay with a debit or credit card, only with cash. A lot of stores will accept a phone number in lieu of a physical card. Learn a neighbor's phone and give them that. Again, remember to pay cash.
We get an additional 5% off everything (except booze) on Thursday (senior discount) and you have to have that enabled on your swipe card or you can’t get the 5%.
I know it’s not a lot of money, but I’ll take it.