Can't say it any better than this:
http://www.youtube.com/watch?v=Wbg2s2bfjhw
or demo it much better than this:
http://www.youtube.com/watch?v=ZuQKr2AkKDU
You have to learn to see your sight. It is a hard concept to explain, but you need to trust what you see without your conscious mind being in the loop. Until you can do that, you probably won't be able to shoot the way you want to.
When talking to yourself about shooting, you should not use words like fast or slow. Nor should you try to go "faster" or "slower". You should let the sight dictate when you shoot, nothing else. The best explanation I can give right now is here:
http://www.youtube.com/watch?v=VN0rTnL1fJs
You will find some helpful stuff here and over time even more:
www.personalshootingcoach.com