To hit solid iron shots it’s important to hit down on the golf ball. This doesn’t mean you want to chop down on the ball. It simply means the club shaft is leaning slightly to the left or towards the target at impact and the hands are ahead of the ball.
It’s important to start out with a slight forward shaft lean in the setup position with the irons. I recommend leaning the club so that the hands are about one inch ahead of the ball. It’s much easier to come back to that position at impact if you start with the hands forward.
The wrist hinge in the backswing will help you to create leverage and power. Once the club is fully set at the top of the backswing, then you want to try and maintain that angle or lag as long as possible on the downswing. Holding the angle between the right forearm and the clubshaft in the downswing is something that all good golfers do. Beginner or high handicap golfers often have issues with casting the club and losing this angle.
It’s important to maintain consistent grip pressure throughout your swing as this will help you to release the club correctly. Tightening the grip or loosening it can both cause a wrist flip through impact and affect your contact with the ball.
Another concept that will improve your contact is staying level with your body and maintaining your angles during the swing. By keeping your knees flexed and having some bend from the hips you will create leverage and be able to transfer more power through impact.
Staying the same height also keeps your swing on a simpler and more consistent path so it’s easier to make solid contact with the ball. When you stand up in your swing or dip down it’s easy to hit thin and fat shots. Try to maintain your knee flex and hip bend until you get the club to about hip height in the follow through and then stand up to finish the swing.