I don't believe in playing 'hard to get'. I didn't really want my boyfriend before we got into a relationship as I was still not sure about whether I was ready to become emotionally invested in someone after my previous relationship ended with my getting cheated on but I bought some time for myslef to become certain about how I felt towards him and... the rest is history. We're still together, two years later. :)
Actually both the girls I dated actually had liked me from the very beginning of course I didn't know that but I didn't have to break my back getting them or anything it was pretty easy.
Come to think of it I've never actually had to work for it when it came to getting girls to like me it just kind of happens *shrugs* well most of the time sometimes I do have to put forth the effort but I don't mind.
Playing hard to get and head games in general is childish. But for my current relationship, I just let us develop as best friends first. I initially tried waiting hours to text him back, not always appearing interested in him, just to make sure he didn't take me or my attention for granted. And he never did, he worried about losing me. So I suppose early on girls just don't want to get attached to easily and want to be chased more then anything.
I don't really play hard to get, I will sometimes go after the guy. But the "relationship" I'm in now, he liked me and I liked him, we went after each other and had sex immediately.
It works better when the girl is interested, rather than her just giving in because he pesters her so much or he makes her feel like she can't do better and should give up resisting (some guys really do this). Go for a girl who is happy to be with you, don't settle for "winning her over."