Awesome Parenting, Really.

[Lace Neil Singer]

My mum would have just said, "Be quiet or the sweets go back on the shelf." She never let me or my brothers get away with whinging and grizzling in public, especially if she was buying us sweets. XD

[BookstoreEscapee]

I would sometimes let a little one scan their own book if their parent had them sitting on the counter. Some parents were smart enough to bring a second copy, knowing full well that the kid would scream (or that the kid was chewing on the item - I was always extra grateful to the parents who realized that I didn't want to touch their kid's soggy book).

[Enjis]

I used to get parents who were teaching their kids early on how to be a good shopper. They'd hold the kid up so I could scan the item it was holding, then hand the child the money, tell the kid 'give the nice lady the money to pay for your toy', and after it was all done, I'd hand the folded up bag to the little one, and say 'thank you'.
I loved that they were getting the kid acquanted with the concept of paying for what you want, and being polite to cashiers.