The Blues have been practising spot-kicks in the build-up to this afternoon's Wembley showpiece, with goalkeeper Cech having also studied videos of the Reds' previous shootouts.
But he admitted all that could go out the window should the match ultimately go the distance.
"I've seen everything I can," Cech said.
"It's all about the moment and if the player is strong enough to keep calm and place it well.
"If he does, you have no chance so, in a shootout, you try to force people to make mistakes.
"I don't know in advance which way I'm going to dive. The procedure comes in the last few seconds before he takes the penalty.
"I might be persuaded to go to the right before the game and then change my mind completely by the way he prepares to take his penalty.
"You can't always rely on what you've seen. You need to rely on your instincts."
Cech's instincts proved useless on Wednesday when he was beaten by one of the best goals Stamford Bridge had ever seen in Chelsea's 2-0 Barclays Premier League defeat to Newcastle.
Papiss Cisse managed to find the net with an outrageous 25-yard half-volley that swerved viciously over the Chelsea keeper from a ludicrous angle.
Cech said: "I've never conceded one like that before. I've watched it three times.
"I even expected the shot and it goes in anyway.
"He meant to shoot. It was clear. I don't think he meant to shoot like that.
"I was almost on the goalline when I made the attempt to save the ball.
"I touched the ball slightly and maybe took the swerve out of it. Maybe I shouldn't have touched it and it would have swerved out.
"Sometimes, things like happen and you say: `Well done'. It's a goal everyone will talk about again and again.
"I'm not happy if I concede but, if you concede one like that, I say: `I don't like that but I can do nothing about it'.
"That's the reality and you have to accept the goal will go in and there is nothing you can do."
Cech was determined to bounce back from that defeat by winning his fourth FA Cup.
"I've won three FA Cups and it would be great to have a fourth," he said.
"It's always special to win the FA Cup."
It would be even more special to win the Champions League a fortnight later but Cech would not trade one trophy for the other.
He joked: "The FA Cup is so small it can fit inside the big one."