"i can probably do better but i decided to talk to you anyway"
Look for a valid excuse to talk to her and segway that into a personal conversation. That may work. For example if you are in class ask them if they understood what you went over today. If you are at work ask them about a project. Then segway into a personal conversation about superficial topics i guess. Then after another conversation go into deeper stuff like family, etc. I guess that woudl work. Excuse to talk to her (usually a question) ---> superficial conversation ---> personal conversation. That could work.
"you're stupid. i'm stupid too. stupid people shouldn't be allowed to breed with smart people, and that means we should stick together. let's go out sometime."
I've never tried a blatant line, especially if the line feels crass to me. The approach has to fit you as an individual. I'm not a player, so what works for me is the "I've never done something like this before, but I had to tell you you're the prettiest woman I've ever seen".
Ok, you can buy me a drink, but don't think I'm giong to put out just because you do. I'm not a cheap slut. If a girl wants to get in my pants she has to take me out, show me a good time, and buy me dinner. Steak works best. New York strip... with steamed veggies... and a diet coke.