This webpage is a good articulation of the classic way of thinking about portraiture, but I should clarify that I disagree with the entire premise of rigid "masculine" and "feminine" posing:
https://www.spencervillebearcats.com/userfiles/88/my%20files...
"… in my opinion, the apogee of the course was surely reached the day we learned how to hold our hands on our hips (doesn’t anyone learn anything at home any more?). Thumbs forward, ladies! Thumbs to the rear, gentlemen! To reverse would not only be gauche (perhaps even worse) but, of course, would result in instant detection and rejection by NASA, the old meanies. I have studied this matter exhaustively in later years, and have found burly construction workers with thumbs forward and mincing fairies with thumbs aft, but then they obviously are not charm-school grads."
If you Google "Sassy gay guy" about half the results have this same pose.