As a power forward or center, you don’t need to be seven feet tall to dominate the post. Just add some strong post moves to your arsenal, and you will take control of the paint.
Your primary weapons are your hips, backside
 and shoulders. It’s more important to use your body to get into position for the ball by creating space and putting defenders behind you than it is to have a big vertical leap.
Always set up on the low block on the ball side. Establish a wide base
 in an athletic stance. Give your ball handler
 a visible target by holding your hands high and calling for the ball. When you perform a post move, never spin so that you fall away from the basket. Always try to get closer for an easier shot.
To improve your post game and dominate your opponents, regularly practice these two drills:

Drop Step

Position yourself at the post, facing away from the basket with a defender behind you. Plant your pivot foot and call for the ball by showing a clear hand target. When you receive the ball, use your non-pivot foot and shoulder to perform a fake drop step. When you feel the defender go for the fake, spin to the hoop on your pivot foot to score.
You have two pivot options, depending on which side of the basket you’re on. If you’re on the right side, you can spin toward the basket and
 power up for an easy score under the rim. If you post up on the left 
side, you can spin to your left and let your momentum carry you to face the hoop, then hit a short jumper directly in front of the basket.

Up and Under

Position yourself at the post, facing away from the basket with a defender behind you. Plant your pivot foot and call for the ball by showing a clear hand target. When you catch the ball, spin toward the basket on your pivot foot and give a strong head and shoulder fake. When the defender goes for the fake, duck under and power up to the basket. If you execute this move correctly, the defender will probably foul you for an “and 1.”