Hi,  I am practicing #3 iron thesedays.  I don’t have much problem with short irons and the driver, but for this #3 and 4 iron, i am usually hitting the ground first before the ball.  I did some internet reseach and watched carefully my downswing, and i realized my left wrist was releaseing the cock too early.
(My driver swing is the same but the difference is the tee height.  So i did not realize my wrist cock issue.)
In short, is there any good way to practice not to release the wrist cock too early?  Some poeple told me just do not use the long iron, but i think this long irons are better than the wood or hybrids due to the accurcy of the ball direction.