You can break down the process of drawing something into components for the purpose of learning. Many of these elements of drawing are well known even to non-artists: composition, light and shade, proportion, perspective, free-hand drawing. Of this latter, I have long wondered in a wry way what its opposite might be, though I must acknowledge it’s a wonderfully expressive term: free-hand, as though to marvel at the degree of control and daring that one sometimes finds in drawing.
The well known terms can be broken further down into even more expressive nuances. For artists, one might list things like contour drawing, cross-contours, blind contour, gesture drawing, drawings that can be corrected through erasure (pencil, chalk, etc.) and drawings that cannot be corrected (pen). For tonality, one notes that there are many ways to create the appearance of light and dark: hatching, cross-hatching, stippling, continuous tone, curved hatching, smudging.
For proportion, one studies accurate, “realistic” proportion in various ways, sometimes by the use of devices such as a perspective frame, or by measuring with the hand or another kind of sighting tool or by training one’s own internalized sense of measure (again another variation on that marvelous free-hand approach — a kind of “point and shoot”). Of course, along with proportion are various discoveries of and uses for distortion. Moreover one uses the angle of vision to enhance the quality of dimension in objects whose forms are more easily recognized by one facade rather than another.
And so on.
However, there are entirely different ways of breaking down the process of drawing. You can break it down in time — drawings made quickly, drawings drawn out very slowly, drawings made incrementally over days or weeks. Drawings that are timed.
Drawings made to understand the nature of binocular vision, or that study the texture of something attempting to evoke the sense of touch, drawings made from memory, drawings whose sole purpose is to understand one aspect of something such as a study that answers a question that maybe only the artist herself is asking.