I try to let stuff roll off my back so I can forget about it as quickly as possible. Only a few bonehead moves deserve comment, and only on a few occasions do I get to address the bonehead. I find rehearsing my response helps. Rather than telling the person off, I tell them what I'd like them to do or not to do. I don't hold back on the anger in my voice, but I make my words polite. Something like, "Please don't do that!" or "Please look before you pull out!"