You can find more uses for your sand wedge outside of a bunker than in it. In fact, I use mine for pitching more often than I do my pitching wedge. It has approximately 3� more loft than the standard pitching wedge and a considerably heavier, more rounded flange. This makes it especially valuable for those delicate short shots that must fly over a trap or mound and then stop on the green, for the sand wedge gets the ball up quickly and with backspin. I also almost always use my sand wedge for pitch shots within 65 yards of the green, even when I am in the center of the fairway and there is no intervening trouble. I do this because the greater loft allows me to go ahead and hit the ball fairly hard. You are less likely to miss a shot when you do not have to baby it. The sand wedge also has many other uses. Try it from the rough, where the heavy blade and flange get under the ball more effectively than a pitching wedge, or from loose or sandy turf, where you need to play an explosion or cut shot. The pitching wedge would probably dig into the turf, but the rounded flange of the sand wedge will bounce up.
When there are no such special advantages to be gained by using the sand wedge and you are in doubt whether to use it or the pitching wedge, then I recommend that you try the pitching wedge. The fact that the pitching wedge has less weight and loft, while a disadvantage in the situations mentioned above, makes it a little easier to control.