Androgyny

There's a big difference between being androgynous and being a tomboy. Androgyny plays on lack of gender-identity while the tomboy is more of a protest against gender-identity. I've personally always been very feminine, without really thinking about it. My gender identity has always been very clear to me. However, the way I look is more vague. I'm a skinny girl and I don't like to dress to exaggerate my bust, so physically I do have a boyish quality. However, nobody would ever question my gender because it's very obvious from the way I am, my gestures, speach etc. So I've always found it exciting to use this vague androgynous side of myself. I actually find that it pushes my femininity rather than the other way around. Mens wear is really comfortable, and can be really sensual if worn properly, especially with a bold detail like bright red lipstick or dark eye-shadow!
If you don't want to go all the way with mens wear, you can start with accessories, like hats, bowties, shirts, tailored pants etc.