Depends on the transgression.

Most of the time I recognize what miserable pieces of shit they are and will sometimes point that out to them while laughing in their face. Other times I'll laugh in their face and move on because I know we both know how much they suck. I do keep a shit list for the worst of them, though. The shit list is actionable and I do get very creative with it. But to be honest, I'm middle aged and there's barely two people on that list. It's not a priority.

Overall, my favorite thing to do is let them know they're not hiding how terrible of a person they are. Best example was some dude and his wife came over to scream at me and I looked at his wife and said, "I'm so sorry you're stuck with this guy. You clearly can do way better." That shut him down so fast all he could do was walk away flustered. Get that ball rolling in dissolving that marriage. *I also had a boss blame me for something I didn't do once and fire me. I dumped all his fuck ups on the HR exit interview and low and behold - he got canned a week later. I guess my answer is I get creative. Shrug.