Avoid the subconscious mentality of "What if I go 100% and still lose? If I go 75% and lose, that's okay, because I know I'd have won if I tried". That's just kidding yourself, and I know because I've done that many times. You really have to not think of the outcome at all, you just have to do it, and do it with all the right intentions.
Mentally rehearse what will happen on the day, up to the point where you first make contact with your opponent (don't try to visualise too much past that, or you will drive yourself insane with the millions of permutations).
Just picture your approach: The ref will call your name, you will stand up, confident. This is where you switch into "game" mode, you're all business now. You slap hands with your opponent, with positive body language that shows him this is just another day at the office for you. Do not concede any superiority, do not let your body language become apologetic. When the ref says "go", you start busy, you start fast, and you threaten him with moves you may not even have. Openings will happen. Maintain that fast-thinking, fast-acting mindset, and that will carry you through your contest.
