Travel to different schools/clubs (specifically ones known for their great wrestling reputation) and practice with them to get new perspectives on wrestling. Start hitting the gym and focus on gaining strength during the offseason. I recommend Defrancostraining.com, it has a free workout program that truly works. Wrestle in the offseason/summer/preseason as much as possible, don't be afraid to try out new moves and stuff like that, and be relaxed and have fun, this is your time to enjoy wrestling without any pressure. Make sure you eat healthy and change your diet according to your goals.
Also, review any videos you have of your wrestling matches, let your coaches critique it, then you yourself review it. See what your flaws were, and work on it, but also focus on learning new moves and adopting new ideas.
Not much else I can think of. Visit Flowrestling.org and watch matches and study them. And... nope. That's it.