Do you have any subtle ways of serving out small retributions?

When I lived in Hollywood, I used to carry around a pad full of those phony gag parking tickets, checking off whatever box on the form I thought they deserved for bad parking (ie, parking that takes up two or more spaces). (There were categories marked, "Total jerk....A-word...Forgot meds...Needs a brain transplant...etc.")

At the checkout I stretch over their shopping to get the divider and say' thank you for helping!'
I haven't been punched yet.

The divider is no big deal, but if I see someone park too close to my car, I'll say something!

😐 no.
I don't fuss over the petty crap.