In the impact, generally, bad players go with the clubface opened and with higher loft. Good player go with a squared clubface and with lower loft.
Let’s see some exercises to square the clubface in the impact.
Knuckles. Stop in the impact area, feel how the hands control the clubface position. Apply this concept: left hand knuckles down, right hand knuckles up.
Training aid indicates clubface position. Place the accessory in the clubface. Stop the impact area, achieving that the accessory points more down than its original position.
Flat surface. Place a box or a wooden board in the impact area. Stop in the impact area achieving that the clubface is squared.
Low shot. Make low pitches or punch shots with a medium iron achieving a lower trajectory than the normal.