Ok situation. Lets say you and her have classes at university (for example) at the same time, but different classes. So you see each other for maybe 5-10 minutes before your and her class starts.
How do you hook up?
My simple routine (not a routine actually, I was using this before I even knew PUA

) :
First time I say hello, how are you doing and ask her whats good at her class blah blah.
Second time I see her I speak some banter as well, but at the end of it I say something "hey you are pretty cool/fun etc lets get to know each other" (I am not English speaking so insert something similar that sounds absolutely natural here in English). I say in in 100% natural and relaxed way and it sounds like I am doing her a favor by letting her to know me

She usually says yeah why not (because we already have some rapport from the first day conversation and I do that only if she sends good signals).
Then she introduces herself (says her name) and I say my name (or even I don't say that) and then say something like "yeah but by saying get to know each other I did not mean just exchanging names because it does not mean anything, I meant lets exchange contact details and meet up sometime to do something fun).
Then either she says - oh yeah sure Or something like "but I have a BF". Second one is not good but I usually say - oh ok so I won't try to hit on you during our meet (again use English phrase that sound natural)
When she mentions her BF its obviously not good but I still try to stay in the game by saying something like above
I see I already wrote too much for such a simple thing. Anyway this works pretty cool for me. But I get bored of that, it would be fun to try something different, what would be your advice in such a situation (when you see her lets say once a week for 5 minutes before your classes start)?
cheers