I have lost count of how many times a robotic clerk became smiling, upbeat, and friendly after I asked their name.@kenasch wrote:
When not on a shop I will stare at a name tag and make a comment about their name. Usually improves service.
Or prepare a burger (two 2 oz. patties with bleu cheese between the patties) and go "Take that, burger chain! My burgers are twice as good as yours, and I can feed a whole family my burgers for what you charge for ONE!"