I would recommend stretching every night to increase your flexibility. Also, at clinics and tryouts make sure your focus is on learning the material... not spending time with friends. Coaches are looking for your dedication from the very beginning; you should show them you want to be there because you love the sport, not because it is cool to be a cheerleader in high school. It never hurts to ask some of the cheerleaders and coaches running the tryouts what they are looking for at tryouts and for the entire season. Just work hard and have fun while doing it! :) Good luck!