On Dexterity, Consistency, and Learning by Doing
"[D]exterity can be acquired by simple exercises with a pencil" (72). One thing Zaidenberg recommends to improve manual dexterity is rhythm patterns like hatching, cross-hatching, cross-hatching at a diagonal, curlicues, zig-zags, etc. (Some people might look at these rhythm exercises and see nothing but doodling, but these doodles improve dexterity.)
"You must endeavor to direct the purposeful completion of the theme originally chosen by first eliciting the 'story' the child has conceived for execution and then recalling that theme to the not-always-constant mind of the child" (72). Ask your child to tell you the story of her drawing, then narrate the story back to your child while she continues to draw.
Learning by Doing (from pages 79-80)
Zaidenberg actually recommends "bribing" children to draw. "Offer an apple or a stick of candy in exchange for a drawing of that apple or candy... A series of tests with all the available easy objects should fix the drawing habit and start the training of eye and hand dexterity... At the same time, make a drawing of the object yourself, not in a spirit of competition but as a means of knowing from first-hand experience what problems your child faces...
"His drawing will usually have a freshness and lack of inhibition not to be found in yours even though your manual control may produce a more skillful approximation of the contours and forms."
Zaidenberg suggests working with basic forms - the circle, the square, and the triangle. "Any four-year-old child can draw a square or a circle in such a way that everyone will know what is intended." For example, to draw an apple, a child can draw a circle, and then add a detail "to give it directed meaning." For an apple, adding a stem conveys "the symbol of an apple," makes a child feel successful, and "stimulate[s] further attempts."
This reminds me of a famous quote by Cezanne:
"Allow me to repeat what I said when you were here: deal with nature by means of
all placed in perspective, so that each side of an object or a plane is directed towards a central point."
If you can draw a cylinder, a sphere, and a cone, you can draw anything!