Have you gone into practice and done the post sessions?
That's the easiest thing to do, you can practice one on one post moves in there for as long as you want and it has the commands listed as you play.
Same for the iso dribbling moves under "freestyle" practice.
In my association im pretty much doing this over and over
1. play next franchise game
2. go practice post moves
3. practice iso moves
4. play next game
It's working well, the post is a bear to master but i've gotten to the point where i know how to string together drop steps, spins, face ups, ect
Still not near mastering it though, seems like it's just going to be a matter of repetition.
Strangely the player im best with in the post at the moment is jermaine. He seems a bit quicker off the spin move than KG and since i normally get a bench player matched up on him i can use that/ a fade away to keep the guy off balance.
JO had 15 off the bench my last game