You start from under the basket. Do layups, hook shots, make sure you're making baskets. You are increasing the range bit by bit, changing sides. Steve Nash posted the workout, I have it somewhere. Myself I always hit few shots not using the legs at all, and then few from the squat position jumping up.
Basically, make sure you hitting high percentage, or get back closer to the basket. Increase range gradually.
here steve nash on youtube: