Ok, so I'm on a train, going down south to visit a university see if I can get in. The girl opposite me is pretty attractive, a brunette with long curly hair. She has a rather distasteful golden earing that looks pirate like, but I'm sure we could make it work. Her skin tone is reasonably clear, with a mild tan. Her fashion sense is casual. She's clearly not dressed up for anything I sit down, I get a text. She notices. I then ask her a question.
"Hey, you're a girl. Would you mind giving me some advice on a... feminine matter" I wave in a way indicating I have no knowledge of such.
"Ok, so I have a friend"
"A 'friend' "
"HAha, yes, a friend. That's the story I'm sticking with. Anyway, this friend cheated on his girlfriend"
*She looks amused and offended*
"and when he cheated she accidently left some very pretty red frilly underware. It was really quite stylish. Anyway, the girlfriend found this. When she asked the guy to explain he said he was thinking of cross dressing and it arouses him to wear women's underware."
*She laughs*
"And she accepted this. She now makes him wear frilly underware everywhere. What should he do?"
Asking a woman for advice on a matter is probably one of the easiest and most reliable ways to get her interest. It's amusing, quick, and not imposing. She can enjoy it too.