[Call_Me_Bitches]

On a busy day, pick up any recent receipts you find at a store, find some of it's items in the store, return them for money in the return department.

Perhaps fade the name or any other personal info off the receipt, you don't want another name on there. Use a pencil eraser to produce an ink shortage. Fade other parts too for realism. But not anything vital.

Be cautious of the prices, i.e. stay in a reasonable range that doesn't seem suspicious, like under $50. Don't go crazy with hundreds. Gotta be honest, if your receipt is bad, but your story is convincing enough, depending on the cashier, they may refund it anyways. I know this because in legitimate cases of lost and bad receipts, I was able to return the products anyways for money back. (yes, lost receipt too - but that was with a buy-back program, so they're a little more lenient with items they can accept back at the time. 80% refund on a $150 item used for several months.)

Stay away from items that have obvious signs of not being purchased like items with exterior plastic security devices.

Don't get mad, don't be silly - if they refuse, just walk away. Reply something politely like "that's fine, don't worry about it." like they screwed up, and your giving them a break. haha, take that Walfart.(put the item back)

If things do work out, leave the store, don't continue shopping.