Load up solo play, find something with marks/lines on it. Go to mid-range. First, see if you can smoothly trace the shapes/lines of the object when you move your mouse cursor over it. Then, see if you can move your cursor to various points of varying distances somewhat quickly and accurately. Finally, imagine someone running across the screen at mid-distance and see if you can smoothly track your cursor across the screen. Adjust your sensitivity as needed until it feels good for you. The AI are terrible as well so they are good target practice.