Mate.
I'm a goalkeeper, and I don't like to blow my own trumpet, but I believe I'm decent enough to defend Cech in this situation. You can't learn to save penalties. It's a lottery, it is impossible to determine where they will go. A goalkeeper has two choices in a penalty shootout. The first is to chose a side to dive, dive about a foot and a half off the ground so you can reach medium-to-high penalties on your side whilst being able to deny low ones with the torso and free arm. The other is to stand still and wait for the ball to be kicked and try and gauge the shot, as Cech did against Ronaldo. Its a high rish situation to do so, but if the ball is near enough to the middle of the goal then there is a good chance it can be saved.
It's all about guess work. You can't learn how to save them.