Every position has its aspects that coaches look for. Below, I have listed some basics that each position should have in order to increase one's chance of being seen and recruited by a college coach.
Overall, coaches look to see if pitchers have good fundamentals, speed, accuracy, and spin. Next, ask the following questions:
Does the pitcher have a pitch she has total command of and can throw for a strike at anytime?
Does the pitcher have a pitch she can locate one to two balls off the plate on either side?
Does the pitcher have a good change up that she can throw for a strike in any count??
For catchers, coaches look for a quarterback, someone who is controlling the entire field. A catcher has to have a voice and the ability to control the pace of the game. Catchers must also have a strong arm, with a pop time (glove to glove) of <1.9 and that is on the high end. Catchers need to have a quick transfer (time the ball enters and leaves the glove) as well. Another skill to have is the catcher must be able to receive the ball and block the ball. A coach does not want to see the ball hit the back stop, no matter how bad the pitcher may be.
A corner must be low to the ground. A good rule of thumb is the closer to the hitter, the lower the player needs to be to the dirt. Catcher is the lowest, then corners, then middles, and lastly outfielders. Corners must have quick reactions, a quick first step. Corners have the responsibility to cover bunts and need to be able to get there quickly to throw out the quickest runners. Lastly, a corner must be quick to move laterally to get the hard hit balls that might otherwise go through those 3/4 & 5/6 holes.
The difference in a short stop and second basemen is arm strength, other than that everything is the same. A short stop has to have one of the strongest arms and quickest releases. Middles need to be able to have range and reach balls in the holes, lay out, get up, and throw a girl out. A really strong middle has both an excellent forehand and backhand. These players keep most of the balls on the dirt in the infield.
Outfielders need to have good speed and a quick first step. They must also have good angles to the ball. A quick first step and good angle to a ball is the difference between a ball being caught and a double in the gap. Outfielders must also have a strong arm. They must be able to throw runners out to any base in the air or on a one hop accurately.
For all defensive positions, players must be able to leave their feet for a play. That is a requirement for all positions. There are many other specifics to each position, but these are the basics that coaches look for in each position. If the above are all accomplished by a player at their position; than that player has a bright future ahead!! If these skills are not yet mastered, continue to work on them and get better. Players can always grow and get better at the fundamentals!
Good luck out there!