I always remind them 30 minutes, 10 minutes, and 2 minutes before we close so they feel their impending doom. Also you can turn the lights of in the lobby lol. Buuuutttt the best thing to do is just ask them to leave, it’s not rude, it’s your job.

Give them a 10 minute warning, shut the music off at 5 mins to close, turn off a few more lights like 2 mins to close then walk to the door with the keys and if they’re still there just say “Hey sorry we’re closing I need to lock up”

I always give them a 5 minute warning before we close.
If they still don’t pack up when close comes, I tell them “hey man I’m sorry but I have to lock up now.”
I have one particular customer that would wait until then to pack up, AND THEN go to the bathroom, so We starting joking and said “any longer and we’ll have to give you an apron and put you to work!”
Joking might not work with some people though, so I’d be careful with that.
Just be apologetic and if they give you crap, talk policy. It’s a safety concern for you to have them in there any longer than (I think) 10 minutes past closing time.

If they’re being particularly slow I walk around the lobby and pretend to do things or stand at the door so they know I’m waiting ( also because we can’t let anyone else in). But that’s more a dick move.

I give everyone a five minute warning, then at close I go up to everyone and say “It’s 10:30! We’re closed!” Since I warned them five minutes before, it doesn’t come off rude or anything. Sometimes people take an extra minute or two to clean up and head out, but never more than five minutes.

If someone refuses to leave I’ll tell them “Sorry, I have to lock the doors or I’ll get in trouble. We’ve been closed for ten minutes now.” I’ve only had to do this like, once.