I don't usually exercise either, but I love to swim and luck would have it that that's really good for building arm and shoulder muscles. 😉 I've also decided to try yoga. I thought it was too girly at first, but damn is it hard! It also builds muscles and endurance.
Things like voice and hair are tricky. My boyfriend's voice is higher than mine, presently, and he is cismale. Then, there's the hair deal. Some cismales, like your friend, have really long hair, haha. However, for me personally, I want to work on deepening my voice naturally and cut my hair (maybe to an androgynous style first).
I really do need a binder, but it's hard to get one when people around me don't know about this yet. So for now, I'm using the 'ole sports bra trick, which is helping some.
As for clothes, I am still hunting for skinny jeans that won't give me away. (Yes, I am crazy.)
Until then, I am busy re- training my body to behave like a man's and trying really hard to erase the irritating girly habits that seem natural to me now.
Thanks for the advice, bro. Good luck on your journey, too.