As bartenders we are occasionally the line of defense for beautiful women that sit at our bar. Over the years, I have developed signal for women to let me know a customer may be bothering them (that will go unnoticed). If anyone is bothering you or being to forward, simply take your cocktail Napkin out from underneath your drink and slide it to the edge of the bar On the Bartender side. It is easy to notice and then it gives me the opportunity to engage and assist.
Always be diplomatic and courteous never trying to embarrass anyone but just resolve the Situation with class.
Tip: Always placing a cocktail napkin underneath the beverage sends a message that you are a professional and organized Bartender.
If you have heavy humidity, and are having trouble with the napkins sticking to the bottom of customers glasses, throw one shake of salt on the top of the napkin. Now the beverage napkin won't stick to the glass.
*Don't go overboard though because your bar top will look like a shuffleboard table.
This tip is so simple yet so powerful, and will seem silly at first, yet my last 3 experiences at bars in the DC area, this small step was not in their process, and it leaves the patron with an empty feeling as they leave the bar.
What's the tip you ask? Say "thank you" or "thank you for your business" as the patron is getting up to leave, or at least as you deliver the final credit card slip for signature.
It let's people know that you, and the establishment value their business. If you couple this "thank you" process with a handshake when some one initially sits down, you are setting up a level of customer service that is higher that most establishments, and that will drive repeat business.