Ball position for short irons should be in the center of your stance. As you progress to longer clubs, move the ball a half of a rotation towards the target.

The "slicer" tends to keep too much weight on the front leg at address for all shots, which restricts the shoulder turn and encourages a steep out-to-in swing.

Someone that tends to "hook" the ball too much will have too much weight on the back leg and play the ball too far back in the stance. Adjust your weight distribution to correct your swing flaw