The majority of all shots on a golf course occur within 150 yards of the green, making a vast arsenal of wedge shots helpful for getting the ball as close to the hole as possible before the putter comes out. The key to versatility around the green is versatility in your bag. By choosing a set of wedges which maximize the number of shots at your disposal, you can help take the pressure off of your putting and lower your score.
Try out any wedges at a driving range before purchasing. When you buy clubs from a pro shop at a range you can often test out the display version of the club before buying, ensuring you will enjoy the way it plays.
Understand the way the grooves on the face of the club affect the spin the club puts on the ball. The more grooves on the face of the club, the more back spin the ball will have as it leaves the club face. The grooves serve to catch on the ball as the club slices through it, spinning it backwards as it launches it off the face.
Understand how the differing lofts of clubs affect how they hit the ball. The higher degree of loft, the greater height your shots will reach, but the shorter distance they will travel.
Select multiple wedges for your bag, so that you have clubs you can hit many different distances around the green, giving your short game versatility.
Place the ball farther back in your stance when you have a lot of green between you and the flag, causing the club face to become "closed," or steeper, to play a pitching shot which runs closer to the ground.
Place the ball slightly forward in your stance, while moving your lead foot away from the ball slightly, to open up the club face, increasing the degree of loft. This technique is useful when you need to play a shot at a flag where there is a bunker or rough in the way and you need to stop the ball quickly.
When more than one wedge will work in a given situation on the course, choose the wedge you are most comfortable playing for each individual shot on the range. For example, if you are more comfortable hitting a flop shot with your lob wedge (where the ball is hit high into the air with a lot of backspin), that is still an acceptable shot, even if there is enough green to play a pitch and run with the sand wedge (where the ball would be skimmed low along the green toward the hole).