One of the most common mistakes that a player makes when he plays an iron shot is how he aligns the shaft.
Players should angle the shaft much differently than the way you angle a wood. The angles are slightly different, but it's really important.
One thing that is similar between a wood and an iron is that the butt of the shaft should point to the belt buckle.
But when playing an iron, because you play the ball in the center of your stance, the shaft should be angled about eight degrees. The butt of the club, though it would point to the buckle if it were straight, should be angled in front of the zippers. You're hands should be in front of the ball when you address your shot.
With a driver, because you play the ball towards the front of your stance, the butt would be pointed towards the belt buckle and at the zipper of your pants. Your hands, when using an iron, should be behind the ball.
It's only about an eight degree difference, but it's important to know the correct way to address the ball whether you use a wood or an iron.