Here is a video demonstrating resistance training for Quarterbacks, which is an etrememly productive training regiment given you have the proper equipment. They use a great term in this video, "the pop", which refers to the quick pop step at the end of the drop. That's a very good way to balance your body at the end of the drop, as well as develop slight movement upfield towards your target. It's a very quick and efficient way to finish both your 3 and 5 step drops. The drills make use of the BulletBelt (www.bulletbelt.com), a resistance training tool.