Well, I first expose myself as in showing who I am and I'm a type of person who has a lot of potential......like ironic humor, intelligence, and understanding and much more.
i do the exposure in front of her and she becomes convinced ( the type of girl i like is good personality and u know...all that other stuff)
I'll give her eye contact and likely she'll be interested and I'll then talk to her...and blah blah blah...
<last time I used this technique on a girl, she was sexually interested as defined in Senor Finger's Weapons of Mass Seduction?>
I'm not really good at defining body language, but I know some and then there is the question of making her want you more...