A swinging bachelor pad, as in one that will actually produce positive feelings in potential romantic partners?
Don't follow the "swinging bachelor" trope [http://fallout.wikia.com/wiki/Love_Machine_Theme] -- that's all about making it seem creepy and stupid. In general, don't be desperate and in-your face about it.
You need art. Bare walls say "I'm a boring empty-headed person!" In college, posters are generally acceptable, but filling your living space up with faddish movies and bands does make you look kinda shallow.
You absolutely need a clean bathroom. Dirty bathrooms say "I have poor personal hygiene!" Would you want to sleep with someone who had weird gunk growing on her toilet?
Both these suggestions are also about promoting positive self-image. It's pretty easy to get mired in your own filth in college. Making your living space feel like a home rather than a squat helps you feel like you're actually going somewhere in life... which, in turn, helps you actually get somewhere in life.
-- Alex