The following is a description of the straight stance, but other than the position of the feet, the rest is common to all three. Where you stand is personal preference and comfort. With sinker ball pitcher, you want to move up in the box and get to the fastball before it has a chance to sink. With a good fastball pitcher, you want to move back in the box. You want to have good plate coverage.
Feet approximately shoulder width apart.
Weight forward towards the balls of your feet, evenly distributed on both feet, or slightly back of center. Knees and waist slightly bent forward. Head and eyes facing the pitcher- don't tilt head. Keep hand and arms relaxed by moving the bat back and forth until the pitcher begins his motion. Stride Approximately 6-8 inches.