In the beginning of my transition (soon after I came out) I also paid close attention to my body language and tried to make it more typically male. Nowadays I don't bother so much with it. Some things I managed to change, other things just never quite got into my head. Mostly I changed the way I walk, to more so swing with my shoulders instead of swinging with my hips, and take longer steps.
I usually stand with my feet at about hip-width distance, cause that's how I learned to stand when I was practicing karate, during my early teens, and it stuck with me. It also helps me keep my balance a bit better, and is as far as I know, considered masculine. Sometimes I also put my weight on one leg, but I've noticed cis guys do that a lot too, especially if they're standing still for longer times, like in a wating line or something. So I think that's not a very gendered thing, from what I've seen. However it does seem to give the impression of being impatient or bored, and younger people tend to do it more than those that are older.
As for sitting, I usually sit with my legs crossed, which is often considered "feminine" but I know that men do it just as much, so I say whatever. I quite often also sit with my knees close together which I hate that I do, but it's very practical when I want to keep my phone, gloves or other stuff on my lap. Sometimes I sit with my legs wider apart, but not as often. Oh, and with just my feet crossed and legs more stretched out in front of me, I often sit.
For me, it's never been my thing to talk with my hands. I always keep them still in my lap or on a table (if sitting), in pockets or just down the sides of my body (if standing). When I grew up as a kid I thought it looked weird when others gesticulated while talking, like.. what are they doing that for? -I asked myself, confused about it. I still wonder the same thing.
My voice has always been rather monotone but in my teens I changed it to sound "more feminine" but that never came naturally for me, so by the time I transitioned, switching back to my more masculine speaking pattern wasn't too difficult for me. Now, I think, as far as I can conclude, that I sound like just about any cis guy, both in terms of pitch and tone. And my mother says I sound a lot like my father these days.
Other things I've been nitpicking about in terms of my own mannerisms have been stuff like how I hold grocery bags, that I point with one finger instead of my whole hand, that I tend to want to keep my arms and legs close to body instead of spread out, how I hold cutlery while eating, how I put on and take off my glasses, how I stroke my long hair away from my face, how I put on and take off any kind of clothing, that I hold things with my fingers spread instead of close together, and how annoying it's been for me to learn that all of that and much, much more is more or less gendered... at some point I just had to stop and learn to be fine with my androgynous body language.
I've been on T for about 5 years, and in transition for 9 years, so I've gotten to a point where I'm mostly not thinking much about how male I appear to others or how well I pass cause I know I pass at this point and have for several years now. That is very nice for me and makes me feel much more at ease and relaxed in social settings, cause I never worry about being misgendered anymore. However, sometimes I worry about coming across as "unmanly" or "feminine for a guy" but maybe that's less of an issue, somehow. I don't know. Can always just say it's because I'm gay, or something, cause that wouldn't be untrue.
As for the alpha/beta stuff, I don't really care. I only think in terms of masculine/feminine/androgynous and male/female. As I'm passing, I don't worry that I'd come off as female no matter how I move my body, so my only worries are how masculine or feminine a guy I come off as. And also how shy/confident, and even also how approachable vs. intimidating. There are many aspects to consider in how an individual is/can be perceived based on their body language. And I think people's stereotypes has more to do with that than anything else, really. But then I also don't want to get off on too much of a tangent about that.