The pitching wedge is used to get you out of trouble, sink the shot to win the hole, or set you up for the winning putt within a couple of feet of the hole. To be effective at using your pitching wedge, you need to not only practice with it, but also understand how to use it.
The basic stance you would use with a pitching wedge is the same one you use for any other club. Your back needs to be straight, your arms straight out, and your knees flexed to get the club behind the ball. The ball is in the back of your stance and it is far enough from your body so that you can comfortably extend your arms. The ball will always remain in the back of your stance near the heel of your back foot, but if you are trying to shorten the distance of your shot then you would move your hands down on the grip and move closer to the ball. This is called choking up on the wedge.
Use the standard interlocking grip with a wedge that you use with another club. For shots of longer distances, grip the middle of the golf grip on the shaft for maximum control. If you need to get less distance on your wedge shot, choke up on the wedge. If you need more height out of your wedge shot, open your grip which will open the club face and pop the ball into the air.
Your short-game tempo is sometimes different from the rest of your game. To pop the ball into the air, you may need to add speed to your swing. To get more spin out of your wedge shot, speed up the club on contact and make sure the club face is open. Wedge shots that require a touch around the green will have a slower swing for more control than do other shots. Tempo is something you have to work on with your wedge and get a feel for different situations.
One of the most difficult things to learn about a pitching wedge is when to use it. Traditionally you use a pitching wedge anywhere from 100 yards beyond the green to right up to the green. If you need a shot with loft to it and spin on the ball, then you use a pitching wedge. However, the pitching wedge has limitations. If you need to get the ball up a steep hill, the sand wedge may be the better club to use. If you need to punch a shot out a great distance but keep it low under tree limbs, you may want to use a middle or long iron that you choke down on. The pitching wedge is ideal for approach shots where you have clear access to the pin and there are few obstacles in your way. But experience will tell you when you should use a pitching wedge or a different club based on the many situations you've encountered on a course.
Many golfers get confused about club selection on the fringe of the green, which is right on the edge of the green, but the grass is cut a little higher than that of the green itself. For amateurs and people learning the game, the fringe is a place where you will always want to use your pitching wedge regardless of how close you are to the pin. It takes time to learn how to properly use a putter from the fringe, and the grass that gets between the putter and the ball can make the shot come up short. Work on fringe chipping with your pitching wedge on the practice green and it will help you develop the touch you need on the course.