Ah, classic daygame AA.
One thing you should know is that you can still go there even if you look like a fool. The day you act like an ass or a creeper to her is the day you should stop going. Haha.
So, I would go get some coffee. If there is a line of people, then when you see her, compliement her (or just say Thank you with a smile) and go sit down. Read a book or something while drinking your coffee. WHen the line cools down is your chance to start gaming her. Trust me when I say that she will shoot you down like a duck in the N64 game "duckhunt" if you try anything while it's busy. Just to be on the safe side, try not to do anything until there are at most 5 people there, and all of them have ordered and have gotten their orders.
So now you game here.
Make sure you bring the right attitude. Be happy and smile. You'll infect her with happiness and smiles as well.
Have the mindset that she's attracted to you regardless of whether she is or not. This will give you confidence and actually help you move forward in the interaction instead of just flirting and bantering and never creating any attraction/sexual tension.
When you open, I suggest going direct from the start. Maybe crack a joke and then go direct.
Ex:
You: Wow, I wanted to meet you when I bought my coffee, but it was so crowded that I didn't get the chance. Since things have settled down, I wanted to tell you that you are one of the cutest girls I've seen all day. I'm not even kidding. I'm (whatever your name is)
Then continue...
or you could just go stright to the direct.
Ex: Hey, I have to tell you something. You are the most gorgeous girl I've seen all day. What's your secret? I mean, is there some silicon in there or something, cause you look amazing!
Now you're thinking she might think you're weird for saying something like this. If you keep a fun, playful attitude, then she won't think you're weird.
Get her laughing and blushing to capture her interest. After, you need her to invest in you. By investing, get her to tell you something personal about yourself. An easy way to do this is to ask her what's her deal? This could mean a variety of things. You could specify and say, "I mean, what's your passion? WHat do you love to do?". Then start guessing random things. Maybe bullriding and make a comment about bullriding. She'll say no, then she'll most likely tell you, or you can just ask her.
Next is for you to connect with her investment. Maybe relation a past experience with whatever she says?
You only have really 5 minutes to do this set since she's at work.
Then you number-close her. Since she's at work, the only thing you can really do is either number-close or set up a date for later.
Make sure you invest because a girl could easily flake on you if she hasn't really invested anything in you; if there is no investment, then you'd just be that funny random guy that she could blow off. The connection you make will make her feel more comfortable around you because she knows a bit about you; you will seem farmiliar to her.
That's it.
So, to recap:
3-8 minute set
1) wait until it's not busy
2) Direct opener
3) Banter with jokes and teases
4) Have her invest
5) Make a connection
6) Number close or set a date
7) Off to the next cute girl walking down the street.
P.s. If this post seems disorganized and shit, it's because I'm really tired, yet I can't fall asleep. xD