Post players need to work on catching, coordination, body control and power. There are all types of post players around. You have your Shaq's and then you have your Kevin Garnett's. Today's game is really making players and moves that they use interchangeable. Some of the best post players in the NBA are guards and some of the best perimeter players are guys 6'9 or greater. Post players we have worked with have all been exposed to ball handling, face up, rebounding, passing, shooting, speed, agility, quickness and back to the basket. We teach them to locate the middle. This means, look towards the middle of the floor as soon as you catch the ball. You then become a playmaker, seeing double teams and finding open teammates. Players should attack the middle every chance they get. After this gets cut off, players will have their spin back and there should be minimal help on the shot.
Post play is becoming a dying presence but it is very important to a successful offense. Post play is a war, it's a battle in the paint. You have to know where to post up, and how to post up. Once you catch it you must have both a confrontational move (move at the basket) and a separational move (a move away from the basket). 3 scoring areas you need to be comfortable at is the low post, high post, and mid post. Comfortable means to be able to have a go to move, counter move, and a 3rd move from each area. When working out on your own always end you workout with rebounding drills because if you can't rebound, you are not really a post.
Start with Mikan Drills and post basics as mentioned in "offensive moves". Work on balance, stance, and catching. Learn to catch and gather (one hand catch then bringing other hand to it). Also, work on jump hooks because they are virtually unblockable if you do them right.