The problem with many nice guys is they are too nice. Yes, there is such a thing. I have been too nice. A man does not need to come running all the time to solve a woman's problems. A guy also can't be a pushover. If a guy is a pushover women will have no respect for him. You don't need to go out and be nasty or mean to girls but you do need to stick up for yourself. If a woman treats you in a way that is not acceptable don't be afraid to say what you think. Don't be rude but pull her up on it. If a woman does not like that well that is her problem.
Former shy nice guy checking in. Work out, don't you dare kiss ass on women (u see tons of kids on gag doing it for example), learn how to flirt in a dominant style, build communication skills, sense of humor etc, ambition and develop a career.
Basically it's all about building your status as a sexually threatening male. serious
Well I'm still trying to improve myself but here's some tips through experience. When a girl wants something from you constantly and she does nothing for you, just say you're busy, you don't need to give her a reason why. If a girl is stepping across some social boundary such as being a complete bitch and you just take it without saying anything back, you're going to look like a complete tool. Sad, but this all has happen to me.