Learn to work with loft
Almost all iron sets come with a pitching wedge, so many players grow comfortable with the standard 52-degree (or less) pitching wedge before they ever pick up one of its more lofted counterparts. That's too bad, because gap, sand and lob wedges add an important scoring dimension and might even be easier to hit. With practice and a smooth swing, anyone can send shots high into the air and land them softly onto the putting surface. When a bunker or creek sits between your ball and the cup, the loft of these wedges allows you to focus more on the pin than the hazard, and more on the benefits of a quality shot than the consequences of a poor one.
Most players know how far they can hit a ball with each club when taking a full swing from an ideal lie. But when a situation calls for a 40-yard pitch to a protected green, many players find themselves simply unprepared to set up for their shot with certainty. At the driving range, rather than spending the whole time blasting away with full swings, get in touch with your wedges by taking different types of swings. This will allow you to see and feel how the ball comes off each club, and how the height, trajectory and distance vary with each loft. Pick out a target like the 50-yard marker and try to land shots as close to it as possible with all wedges. When it's time to face challenging pitches in the middle of a round---perhaps a high lob that needs to land between a creek short and a steep ridge long---you will have the confidence to attack the hole with any of the wedges in your bag.
Practice sand play
Bunkers can be terrifying for players who don't understand what it takes to get out of a trap safely. So rather than practice in the sand, they go through their rounds hoping to avoid it. Learn to hit basic bunker shots with a sand wedge and you will immediately shave a few wasted strokes from each round. Not only will it make escaping from green-side traps less of a hassle, but it allows you to take risks from which you would typically shy away. Once you ace the basics of sand play, learning to escape from more challenging situations---like plugged or downhill lies---comes much more naturally.
Stay smooth and firm
Players lacking confidence in their wedge play often chop down on the ball around the greens, mainly because they fear striking the ball too hard from such close proximity to the pin. They drive the head of their wedge straight down toward the ball and either stick it into the ground behind the ball (resulting in a chunked shot) or skull it clear across the green in any direction. Visualize sweeping the clubhead directly underneath the ball. This allows the loft of the club to pop the ball into the air, while you do your job by providing a smooth and firm stroke that accelerates through the ball. Your scores can't help but improve.