I copy and paste this a while ago into my electronic scrap book. Hope it helps:

The Challenge

No wonder why the girl is ridiculously good looking, that's the reason she got the job in the first place. So instantly you are gaming a 9 or 10. The other challenge with gaming bartenders is that they see guys at their worst; usually prowling, boozing and fighting. So you will instantly be labelled as one when you attempt to hit on her over the bar. So your first words are the most important (as well as what you order).

How to Get It

Firstly don't order triple "sam bucka" for you and your mates because you're only going to get fucked and ruin your chances. If she wanted to chat to a drunken guy she has 200 others to pick from.

Pick your timing perfectly because even a second out and you could have lost the chance. Don't start chatting to her when she has 10 other people to serve, but don't lurk around at the bar lurking, waiting for her to finish.

Start discussion but avoid the conversation of her job (that's what every other guy chats about) so talk about other exciting things in her life such as hobbies, passions and holidays. But try to make her do most of the talking with these things as she is very used to lame drunk guys reeling their life off to her over the bar.

Escalation

You must be direct with this, because to be honest you're not going to have a lot of time to close the deal. She does have a job to do! Having come from a bar background I understand how annoying it is to have to listen to some girl who wont close it whilst trying to serve customers.

You should go straight for the number, but don't plan to take her on a date to town, because that's what she does for a job! You should do something fun and exciting in the day, before she goes to work. That way you put a time constraint on the date because she must go to work at some point.

Maintaining It

Don't run around tell everyone how you hit on the bartender at (x) bar because you'll only put her job in jeopardy and your reputation too. If you want to keep it going with this girl you must keep it out of work as much as possible! In any relationship you must keep business and pleasure separate!