Where is a girl touched and that gets them horny from being touched there?
It varies from girl to girl, one girl may like to be touched somewhere that another girl hates being touched. Talk to her about where she likes to be touched and you'll find out. If you don't want to ask her then you probley shouldn't be touching her that way until you have some communication skills built up.
personally I liked 2 rubbed on my lower back, kissed on the neck, rubbed on the stomach and rubbed on the inner thigh. but don't do the inner thigh unless you have da type of relationship where she's comfortable with that.
Kiss her neck and her ear, while your doing that grab her hair, NOT HARD and like run your ands through it. :) You have to experiment though, all girls are different.
It really depends on the girl, but try the neck...