Need some advice. Im good, actually excellent at hooking a girl into a relationship. Only thing I have trouble with is keeping the girl around once I have her. Either I get bored or I can tell she isnt so happy and crazy about me anymore and I leave her. I've only been left by one chick and she was a crazy stripper.

So my question is: Whats the best advice you can give to keep a girl around and keep her extremely happy?