I had a bad problem with my irons recently, went to the pro and he asked me about my faults, topping it, snap hook left, block right etc He wrote down on a piece of paper what he thought the fault was, then got me to address the ball with my 5 iron and showed me that i was about 3 inches too close to the ball (measure by putting the 4 iron head behind my left heel with the shaft pointing out in front of me, the ball was part way down the grip when it should have been right next to the end of the grip/shaft!), moved it out there and every shot was going great. It was all to do with having the ball too close which in turn meant i didnt have enough room to clear my body through the turn which brought my hands into play!