Most Helpful Girl
Music, movies, life aspirations, experiences, interests, etc. Just bring up different things to find out where there is common ground.
Most Helpful Guy
Well, besides those obviously rehearsed-type questions, here's something I wrote up about this:
"Ask her to tell you a story. Ask her to ask you questions. Ask her what she wants to talk about. Ask her what's on her mind; ask her what she's thinking about. Ask her about herself. Ask her about her opinion on something. Ask her about anything about her, because girls love to talk about themselves, and it's nice to show that you care about what she says and thinks."
And yeah, you'll probably come up with random stuff to say anyway, if your conversation goes ANYWHERE. I think it's pretty normal for girls to be able to carry a conversation.