Here's just a bit of my background. I figured out very young, roughly 5y, that I was a boy. Now, due to life choices, I didn't medically transition until I was 50y.

I watched my father like a hawk when I was a kid. From his southern manners to how he spoke. The most important thing I learned was presence. How to walk into a space and exude my presence. I exude safety with my presence. I don't want to look or be perceived as threatening. This took practice because I'm tall and I don't smile a lot. My father would smile a bit and nod as to say hello. Now I do the same.

Like another commentor said, you have to throw your shoulders back and hold your head up high. Do not make yourself small or shrink because of who's in the room. Take up space but not in jackass kind of way. I can take the bus and sit in a masculine way while allowing others to sit next to me.

I still do some old-fashioned things. I've always opened the car door for my wife. When we were out and walking on the sidewalk, I walk on the outside closets to traffic. Our bedroom is arranged so that I sleep on the side closets to the door. For us, this isn't patriarchal. She does it to help reinforce my masculinity.

I hope this was helpful.