The "catch-22" of training for any sport or technique is that in order to be good at it, you must repeat basic movements over and over and over. Yet, doing so is boring and most people quit an activity before they have mastered it.
The key way to resolve this is by disguising repetition, or making the same thing seem different. The ability to disguise repetition is one of the most important skills an instructor can possess. This book provides the drills themselves, but also includes many optional variations to each that can give endless permutations.