I have to agree with ginsu here. Play shape by having a specific place you want the cue-ball to end up after you sink the nine. This will keep your focus up.
I agree. If you change your mind set to only making the ball you leave a void in your concentration. This will allow negetive thoughts to invade your mind. Give the game ball the same attention that you gave all the other balls. Play a specific spot for the cue ball to wind up at. Pocketing the game ball will become automatic.