Here are some things that I looked at when I used to recruit and what other coaches look for as well that many players seem to overlook...
Grades. Nothing is more valuable to recruiters and nothing is more undervalued by players. I can't stress how important this is.
How you carry yourself on the field. Having your shirt tucked in, hustling, respecting teammates, opponents and umpires.
How you carry yourself off the field. How you talk to and act to your teachers, coaches, classmates and family. For those of you who have cell phones the worst thing you can do is have a voicemail that says "Yo dawg this is (your name), hit me back" and then have some song blaring in the background. If there is a chance of someone calling you that maybe associated with a college or pro team your voicemail should say "You've reached the voicemail of (your name), please leave a message. Thank you". I can't tell you how many players don't understand how something that small can have a big effect. When you get to talk to coaches make sure to address them as sir and be respectful.
Are you emotionally mature? Can you handle the pressure of pitching in big games and big situations or do you let mistakes rattle you? Do you know the game and the rules? Are you confident? Aggressive? Or do you look as though you'd rather be elsewhere. Scouts are looking for guys who want the ball.
Offseason work. I come across so many talented players that if they were to put the work in in the off-season that would be the difference to making it to the next level or not. You hear stories of guys like Derek Jeter and Tony Gwynn taking hundreds of swings in their backyard everyday in the offseason, etc. Your high school season is just a small part of the year. A lot of players seem to forget that college coaches see many more summer and fall games then they do high school games. I had a younger brother that had a great high school career. He would wake up at 5am and work out for an hour and then do tee work for an hour until he had to go to school each morning. That was dedication.