Updated: Nov 9, 2018
Doing quick sketches of the model is a great way to help artists focus on the essentials. A variant of this exercise is doing two overlapping sketches of the model on one piece of paper. This both aids in honing-in on what features are important to convey about a pose and to also get an appreciation of how the body moves.
These four examples are also from the 2013 Summer Art Experience. Eight one-minute sketches of the model (Kiah), two conte crayons (purple and yellow) on newsprint/butchers paper, 60 cm by 77 cm.
I have played around with the contrast and lighting settings of the original photographs in order to show both the yellow and purple crayon used for these drawings. Accordingly, phantom blue tones are visible in these photographs that are not actually on the newsprint sheets themselves.