STEP BY STEP

Once upon a time, before art teachers employed video or Photoshop to demonstrate the progress of a drawing, the Famous Artists School helped popularize "step by step" instruction:

Original drawings by Harold von Schmidt, "How to Draw a Dog"

Even today, the Famous Artists School training materials remain a marvelous record of the working methods of some of the country's top artists. 

Von Schmidt, an excellent draftsman, is underrated today

Illustrator Seymour Chwast couldn't draw nearly as well as Harold von Schmidt but he was a smart guy who recognized that by reversing von Schmidt's steps he could create a clever joke about deconstruction and reductionism:

Similarly, the following series from Guy Billout was focused more on conceptual stages than the steps necessary to  create a likeness:

In the next example, Chwast offers an utterly delightful perspective on the progress of a drawing:

Many a truth is said in jest.  For Chwast, the lightning bolt of inspiration 
was more important than years of studying the craft of drawing.

In this final example,  Richard Thompson speeds up and slows down time, introduces the childhood game "Chutes and Ladders," and shifts back and forth between alternative realities: 

 
Video and Photoshop have become superior methods for demonstrating the kind of steps that Harold von Schmidt was teaching, but note how static drawings still permit more freedom and creativity when it comes to demonstrating conceptual steps.

For von Schmidt, the space between drawings only reflects elapsed time.  For artists such as Thompson and Chwast it reflects not only elapsed time but also movement between worlds or perspectives.  It allows the artists to play ontological and surrealistic games which, while not as linear, are every bit as educational and truthful.