You don't have to be hostile, just firm and confident. Tell the guy that he needs to leave and not come back. If he starts to cause a problem call the police immediately. We aren't paid enough to risk our safety.

We started just dropping our tips super often when we thought people might be taking them. Maybe just start emptying it before he comes?

He shouldn’t be stealing at all but I think saying “how low can you be to take 2 dollars” is kind of insensitive. Do you know how many people are broke and homeless out there? It’s common sense why he would take two dollars. Not saying what he did was okay because it isn’t at all! Just whenever you see him maybe remove the tip jar away from where he could reach in and then get him his cup of water.