If your iron shots are flying low and short, it might be because you are not using the leverage of your body to hit down on the ball. In this video Aimee Cho demonstrates how we can more effectively use our body, so that our irons hit down on the ball with the strength of our body. Which in turn creates a higher and longer ball flight.
Toward the end of the video, she talks about aiming about 6 inches in front of the ball. That makes me wonder if by aiming in front of the ball, we can sub-consciously hit down and use more of our body, without forcing the correction. Take a look and tell me what you think.
Update: I found looking 6 inches in front of the ball too hard for my brain to accept. However, I tried looking at the front of the ball, instead of the back, and my strikes were so much crisper.