Here is the University of North Carolina Swimming Head Coach, Rich DeSelm, on the topic of Sculling. The three exercises presented by Coach DeSelm are designed to set yourself up for a better overall stroke. Work on these drills in practice so that you are more confident in your form on race day.
All of these sculling exercises will enhance your propulsion due constant movement. Your stroke will be smoother and have better rhythm when using the material provided in the video.