Keep in with the staff... Cardinal rule.
The 'customers' come & go, and there are a number who use this 'paying guest' crap to give themselves more 'importance', and some moral high ground over people..

DO NOT have an big ego, musicians.
It gives you the moral low-ground.

Moderation in everything.
.. although you would have to include 'moderation' in that equation, also
Treat people like people until they stop treating you as such.

Then take the head off them!

And that goes for the musician as well as the customer