My daughter is getting ready to start her senior year in college. She's been pitching against very high level teams pretty much her entire pitching career which started when she was 11. She had some very good success in HS. Her travel teams always played against the best competition from throughout the country. Her college sophomore year she finished in the nation's top 10 in K's per 7 innings at the DII level. She averaged over 10 K's per 7 innings that season. She was off slightly last season only averaging 7.6 K's per 7 innings. She knows how to make hitters miss.
Through the years she always kept it simple. Since she was playing 14U she has never thrown a fastball in a game. She throws 5 different pitches during a game. She'll throw a rise, drop, screw, change, and curve. All of her pitches move through two planes when they break. She will vary these pitches slightly by changing the speed and spin on the ball. She can vary each pitch slightly to make them look different enough to keep the hitters off balance. No two ever pitches look the same. The one thing she has worked very hard on is disguising each pitch. Here delivery is nearly identical for each pitch. It irks me to no end to see girls in circle doing all kinds of weird gyrations for each different pitch. If you keep it simple it's less likely to break.