>>41 OP
Find something distinct about the girl you want to strike up a conversation with. Make a comment about the distinction and ask a question. Like:

you: Nice Mojave 3 t-shirt. Which is your favorite album?

her: "Puzzles of You" is my fave.

you: That's a good one, but I really like "Ask Me Tomorrow" best.

her: Should we have sex at my place or yours?

Ok, so that may not happen, but the best bet is to ask a question to get her talking.