>>2572699>>2573874i'd say your approach on this vastly depends of you wanting to draw a single person being nude or 2 or more people interacting sexually.
thought faces and head angles are important, my priority would be bodies (anatomy + proportions) and poses. you'd achieve that best with drawing from life. do not try to learn anatomy from other artists or from comics/anime/etc.
if you wanna draw porn then bodies and propotions and poses are also important, yes. but please for the love of god don't slack off on hands. interaction is so fucking important and i barely see people talk about it because most people just tell you to "haha just look at porn xd"