If you are looking to improve speed and agility, consider the lateral 2 in 2 out agility ladder drill. The footwork is fairly simple, and is commonly used during sports play. The "2 in 2 out" is the foot pattern you will be using, and means that two feet will enter a square and both will exit the square.
The key to all agility ladder drills is to stay on your toes. Pretend the ground is a hot surface. It is advised to practice all drills slowly. Once you become comfortable with the footwork, try to increase the speed of the drill. Instructions for the lateral 2 in 2 out drill are as follows:
Begin by standing behind the first ladder square (face perpendicular to the ladder). Your lead foot is dependent upon the direction you are moving down the ladder. If you are moving to your right, then your right foot will be the lead and vice versa. Take your lead foot and step into the first square. The opposite foot should enter the square immediately after. As the second foot enters the square, your lead foot should exit the square. The trailing foot should follow shortly thereafter.
Advancement down the agility ladder always takes place with the lead foot. The trailing foot essentially mimics the movement of the lead foot. Be sure to do the drill going both ways.