There's no secret to being a good wrestler. It takes hard work. If you put in more time on the mat, and you're in better condition than the other guy, you'll do fine. You don't have to get mad, or "crazy". Set the pace, set up your take downs and execute smoothly. If you end up on your back, you'll never be there longer than 2 minutes, so fight like your life depends on it. IF you're getting railed by a guy who's technically better, stay in the match, he might gas and make a mistake.
Summary:
1) Leave no doubt in your mind that you have worked harder than your opponent.
2) Set up and execute
3) If you win, act like it ain't the first time.
4) If you loose, shake his hand and walk off the mat. If you throw a fit, you'll cost your team a point and your coach will make you hurt.
5) Have fun