Many young players waste valuable time waiting for their turn to hit. They stand in the on-deck circle and talk to team mates or take lazy swings with the bat. Poor on-deck preparation reduces their probability for success. Good on-deck preparation should include the following:
Position yourself in the on-deck circle so that the pitcher and home plate are both in view.
Quickly loosen up your muscles by swinging the bat back and forth and over your head.
Take your stance and focus on the pitcher.
When the pitcher releases the ball, stride and then swing hard, the same way you plan to swing when getting up to the plate. Notice where the ball is released from.
Time your swing so that your bat head crosses the plate before the ball does.
Make timing adjustments on the remaining pitches until it is your turn.
Analyze the game situation. Will you want to drive the ball to the right side? Sac fly? Bunt? This is the time to think through the situations that may come up for you. You can not think and hit the ball at the same time.
When leading off an inning, do not waste time talking. Go time your swing.
At least after a swing or two, do not use a bat donut on-deck. This will throw off your timing (studies have found that the probability of hitting the ball on the first swing is lower for players using a donut on-deck).