Hoping there's someone similar out there -

I'm 29. By this time, I've mostly accepted who I am, and I'm a "nice" guy. I don't like stepping on people's shoes, don't like making people feel bad, don't like disagreement. I'm pretty easy going and pretty forgiving, it takes a bit to get me riled. While I'm not naturally assertive, I am confident. I've excelled at work, taken on leadership roles - president of a fraternity, president of student body groups, etc - I'm the sort of leader who is calm and composed.

With respect to girls, my problem, I think, is difficulty showing intent, difficulty getting that man-woman vibe going. In terms of masculine/feminine energy, I lean more towards feminine, and sometimes I find my interactions missing dynamism. The other night in tango class, my partner mentioned that I needed to be a little more assertive and lead harder. (but I didn't want to step on her toes)

In short, I think I'm missing that masculine, killer instinct. My energy is too placated. I'm shy, maybe afraid to go for it. I'll see it in other guys, they may not be the best looking or whatever, but they seem to know how to lead and ultimately, how to hook the girl. Whereas I just have nice conversations with everyone.

Obviously I'm not always that "nice" guy, there have been times I've felt that assertive energy, but it doesn't stay. My question is, for guys similar to me, how have you developed that vibe? What were some things you realized or things you needed to specifically work on?