Creating a consistent, solid strike is the key to taking control of your pitch shots. To create consistency you need to keep your lower body stable and quiet throughout the swing, allowing your upper body to stay on top of the ball at impact. This position will allow your shoulders and arms to create a downward arc through impact and result in a solid, crisp strike.
The most important thing with shots like this is to practice. Keep those legs quiet and build your confidence with these shots on the practice ground, from here you take your consistent play to the golf course and make those all important up and downs.