I've seen you've been asking the same in several threads.... Ok, i will tell you the secret:
1. Aim.
2. Putt.
Now comes the tough part.
3. If you miss, next time you have that same putt, remember where you aimed and how hard you hit it and try something different. If you sink it, next time you have that same putt, remember where you aimed and how hard you hit it and do exactly the same. Easy uh?
P.S. If green slopes left to right, you have to aim LEFT of the hole and if it slopes right to left, you have to aim RIGHT of the hole. :P
Just kidding.... Have fun!