I think this idea that you get seen as a friend because you act in a certain way, but could be seen as something more than a friend if you act in a different way, is not really that valid.
For me it's simple, a girl is either attracted to you or she isn't. If she finds you attractive and you get on as friends then more than likely she is going to want more; if she doesn't find you attractive then she will just want to be friends.
When this question comes up people always suggest different forms of behaviour, don't be too nice, don't compliment her too much, act off with her sometimes etc....but you are naive if you think that behaving in a different way is going to change how a girl views you.
If you turned it round, and there was a girl who you weren't attracted to, but thought had a good personality and you got on well with her as a friend....then she reads up the 'rules of attraction' and starts being flirty, taking the mickey out of you and so on, would you suddenly find her a turn on? I doubt it!