One way to express your femme side internally is by adopting a more feminine approach in certain things you do (assuming there is a "feminine" approach

). I can think of two examples from my own life.
When my children were babies, I took pride in being as adept at changing, feeding and caring for them as my wife. In fact, I felt (and still feel) that I loved them with a mother's love. This was not so evident with my daughter, since fathers are expected to be affectionate with their little girls, but it definitely was with my son (for that matter, I am still affectionate with him, and he is almost 22). I remember being at his school for a meeting with teachers when he was about 15. He came into the meeting to participate, we saw each other, and I stood up and we hugged each other. It was nothing big to us, but I remember the principal commented (favorably) on it.
Also, in my adult life I have always cultivated friendships with women - not romantic attractions, just friendships. I love talking with them about their families and their interests. And a few years ago, when I was in a band for a while, I often approached things thinking, "What would Erin do about this?" I was the new member of the band, the drummer, and I decided I wasn't going to be loud or flashy, I was just going to keep good time. Any suggestions I made were made in much more low key fashion than I normally would. As an external expression, I almost always wore to rehearsals a Jacksonville Jaguars jersey that was too big for me, not because I like the team (I don't, particularly), but because it is mostly teal, one of my favorite colors. I also love the way the acetate feels on my arms while I play.
I'm not that kind of girl.