What a wonderful topic. I have so many thoughts on this; I’ll do my best to add something useful.
In reply to Synne’s observation: I’ve had the same shift since becoming a mother. Isn’t it interesting what that does.
I’m also with Astrid, in my pursuit of finding balance between my feminine and tomboy side. Last week I only wore slouchy trousers. This week only fitted dresses. So it’s more of a going back and forth between the two. But when I wear a tomboy outfit I need to add something feminine (a low heel, dainty earrings) and when I wear a dress, I’m inclined to add shoes and accessories with more of a yang quality.
My own interest in fine-tuning the yin-yang of an outfit has to do with my body as well as my personality. My body is very yang and I need to balance that out somewhat because I don’t want to actually be mistaken for a man. Which happened a couple of times when I was a teenager and we all wore wide-leg jeans and hoodies (and my hair was short). I also have a big masculine side to my personality (see how I’m bragging about it already :)) that I tend to tone down a bit to make life easier for myself. The Sheldon Cooper kind of masculinity (boyishness?) though, definitely not the McGyver kind!
(EDIT: PS: I applaud Angie's attempt to scratch the words from her speech. In writing this down I'm seeing how hard it is not to use masculine/feminine and how, at the same time, using those descriptors affirms existing stereotypes about our identity.)