Invest in buying nine 9 balls. Rack em up and every shot will be at a nine. Practice playing like this for a couple of weeks and then when shooting the 9, it'll be a piece of cake. Seriously though, I think in our mind we tend to treat the 9 ball differently then the rest of the rack. It is the only ball that counts, so we tend to be too cautious. We take a little longer while down. As someone else said, you need to execute, don't study the shot and try and aim to carefully. See the ball and stroke through the shot. Don't punch the CB. Don't try and steer the CB. Keep your arm loose, stay in a rhythm. Concentration and believing in yourself will get the job done.