Space Away From the Baseline
Many post opportunities are lost because the post player winds up too close to the baseline. The result is he becomes easier to defend because on a baseline pivot he will find himself behind the backboard with no way out. The defense has an easier time defending the more limited passing lanes into the post and the result is less post touches.
When taking your position in the post, straddle the first lane line above the block. Do not wander or get pushed lower toward the baseline. Playing above the block not only allows you to turn in both directions but also forces the defender to make some decisions. If the defender plays on top, there is now enough room on the baseline side to create a passing angle. If the defender plays low, there are wide open passing lanes from the top. If the defender decides to front you, there is plenty of room over the top and a great possibility for lob passes.
One Way Defense
Once the defense decides how he is going to play you, don't fight him. If he wants to play over the top, fine. If he chooses to play you on the low side, let him. It will make it easier or you to find him and beat him.
However, only let him play you one way. If he plays you on the low side, do whatever you need to do to keep him on the low side. Do not let him come over the top. The same goes if he decides to play you on the high side. Pivot, seal, block out but do not allow your defense to change sides. Once you have him held on one side the ball will find its way in. Once you have the ball, it is easier to make a solid scoring move.
We all have moves, pivots and shot we are comfortable with and feel that we are effective with. Doesn't it make sense to make that move first? When you receive the ball in the post, don't worry about what your defense is doing, make a move you are good at and feel you can score with. It doesn't matter if you are defended, if it is a move you are good at, you will score a fair amount of the time. I use a phrase often, "If you can't score on your move, how are you gong to score on his." Don't let the defense dictate what shots you take. If you like to make a front pivot jump shot, make that move looking to score.
If you find that when you make your move you are defended, counter. A counter is an aggressive adjustment to the defense that gets you a god scoring opportunity. For example, if you make your pivot and find your shot defended, counter with a step-through move and take advantage of your defender's position.
Every pivot has a counter. For me, it goes like this: front pivot – counter is a step through; drop step – counter is an inside pivot; inside pivot – the counter is a sweep move.
The variety of shots that come from making a pivot and then a counter is limited only by your imagination.
Do What You Are Good At
You can't be good at everything. Pick two or three things you are good at and become very good at them. Don't worry about having 10 or 20 moves in the post. Simplify to just a few things that you are good at and stick with those. The simplicity will lead to more decisiveness and the success will lead to more confidence. That combination will make you much more difficult to play against.
Hopefully these few simple points will help you become a more effective post player.