In essence, pitching is a series of perfectly timed movements, so preparing to pitch should also be sequenced and timed for perfection. After all, the best pitching performances are called "perfect games."
The first a thing a young pitcher should do to prepare for throwing strikeouts is...not pick up a baseball. I know this may come as a shock, but consider the following. As a high school athlete, ideally you've been playing basketball, hockey or football and giving your arm, body, and mind a needed break from baseball. So starting back to baseball in January or February, you probably haven't pitched in months. You need to go slow at first and prepare in a clear progression.
The most important aspects of preparedness are: (1) going into the season healthy, with your body primed to stay healthy; (2) understanding your arm and body, and knowing when to rest before and during the season; (3) improving your strength relative to your body weight; and (4) communicating with your coach and parents about how you're feeling as you prepare for and enter the season.
Regarding staying healthy, here's what Eric Cressey, an expert in training baseball players, says: "Contrary to popular belief, playing [baseball] year-round is not a good idea. In fact, it isn't even good enough to qualify as a bad idea; it is an atrocious idea. If you want my ideal competitive season for a youth baseball player, it's to pick up a ball and start tossing around Thanksgiving, progressing to bullpen work in early January—after long-tossing distance has been progressed."
Do you know what the safe and appropriate pitch count is for your age? Besides how you feel, the pitch count is one of the best ways to protect your arm from injury. These recommendations are made by field experts. Following a pitch count is much more accurate and useful for protecting your arm than an inning count.
Have you developed a plan to work toward that pitch count? In other words, you need to set up a program of flat ground throwing with progressive intensity and volume, followed by long tossing and then pitching off a mound.
Have you thrown out the radar gun yet? How hard you throw does not automatically determine your success. There are a lot of hard throwers working at Wal-Mart and playing slow pitch softball. How you pitch and stay healthy is what will make you successful. Check out this Eric Cressey article.
The biggest factor limiting recovery for a pitcher's arm health is not the build-up of lactic acid, but the steady loss of range of motion over the course of a season. Restoring range of motion after each outing is critical for maintaining the health of your arm.
The Thrower's Ten is a good set of functional exercises for a young pitcher to learn and to use for arm protection.
Improve upper-back and scapular strength by performing Face Pulls, Single-Arm Rows and Isometric Rotator Cuff Strengthening in half kneeling position.
Your pre-season progression should look like this:
Watch Cy Young Award winner Justin Verlander's off-season workout.