One of the reasons we get so many knee and ankle injuries is that we don't practice simple athletic movements in a controlled environment before going full-bore into an athletic competition. Learning to change direction with speed and power in training can save you from experiencing these injuries. Here's one way to do it.
Do rapid back-and forth shuttles with one step in between direction changes. In other words, you go two steps to the right, then two to the left.
This really focuses on lateral change of direction, and it's a great way to improve coordination and leg strength/power while building structural integrity in the lower body. Higher reps will also scorch your quads and lungs.