Hitting it CRISP is all about timing. Timing (in golf) is specific to the timing of the weight transfer – especially your weight transfer back to the left side. And this timing is dictated by the PLANTING of your left foot. Once your weight transfers back to the left side, your entire upper body rotates about a PLANTED left foot.
One of the best training devices that I have come across is the Tour Foot. (I had no idea it had become so difficult to source…when I bought it, it was readily available). It FORCES the left foot to stay planted – both during the backswing and downswing. The left foot has a tendency to slip – especially during the downswing.
Try hitting a few shots on the range with the tour foot and see if it helps your timing at all. I discovered (much to my delight), that I was getting effortless distance – and the irons felt crisper than ever.
As an alternative, you can purchase SPIKED golf shoes for practice on the range. While not as effective as the Tour Foot training aid, the shoes still do a decent job of keeping the left foot planted.