Ok, thats should be too easy, especially in PES6 or WE
ES2007..
There are different techniques:
1. You may use :square: :x: then direction to fake. If its done on the right time the keeper will normally go in the animation of blocking the ball and that will allow the time to pass by him and scores....
2. Another easier method which requires lil of timing is to release :L1: before reaching the keeper and then sprint again using :L1: at an angel direction passing by him.
3. Dribbling past defenders the slower you are the more balance you have to control the ball. So when you dribble you need to accelerates when its necessary.
There are many other styles >>> all you need to be creative with the buttons......
----------------------------------------------------