Bartender game

This is mostly about how to game girls while working in a bar which can get quite busy during the nights. The good part is that the dance floor is right besides the counter, so it's easy to spot people from there. Sometimes I just call them from behind the bar and they come (well what a surprise, horny drunk girls coming at command when a bartender calls for them). But besides this, what advices do you have in general?

A more particular question would be... how to refuse girls in such a way that it shows high value? You know, all over the world, regardless where you are a bartender, women try to flirt with you to get things cheaper.

Well guess what, I do not do it. I do not give free stuff (or cheaper for this matter) besides to the people that I work with and are out in town while I am on a shift - and I give it to them 'cause they also do the same while they work and I am out. Plus we are work mates, they mean much more than just the next girl.

Now I would not care that much about the fact that I have to reject them - if I wouldn't know about "The Game" and what huge opportunities are out there. I just want to find a playful way of doing this while also trying to engage them into a conversation and not look like a jackass or a cheapskate.