Half wedge shots are very important for the advanced player and build the basis of a full swing
A common mistake on the backswing is to hinge instead of cock your wrists, a perfect drill to help fix this is to pre set your backswing by cocking your wrists right up in front of your face at address and then turning into a full backswing
Focus on your left wrist at the top of the backswing and start of the downswing to get to impact properly, many players have a cupped left wrist which changes the angle of the clubface, this causes an open clubface and results in casting and manipulation during the last portion of the downswing