Pay your totall in change. When ever she says something yelll WHAT? Say you want cloth bags when they only have plastic. Put all your items up on the register and when she is done scanning them put more on. Ask if they have porm. My friend did that and he got kicked out xD
get ur credit card/money drop it pick it up and act innocent -repeat alot- when ur done say "oh nvm i dont want this stuff u can have it" then u pick it up and drop it then pick it up, give it to them and leave.
At the grocery store, jump up on the little coveyer belt and start dancing. Then you slap the person, take the little thing you speak into and start singing a Michael Jackson song. Then turn the conveyer belt on full blast and do the moon walk XP Yeah I know I'm random.