it all depends on the girl man. If she has problems with her dad (he is a drunk, abusive, w/e) then be an asshole to her. If she has a perfect family life be the good guy. Works everytime, you just need to be able to recognize who has the daddy problems. It is the girls who hate their dad's who are gonna be good for a quick fuck, while the girls who don't have baggage will be good for a relationship.
or just slip her a roofie