Here’s a plan for the typical three-hour quick sketch session:
First half-hour—One- and three-minute poses. Follow the example of Michael Hampton’s Figure Drawing: Design and Invention, p. 38, and focus on the placement of landmarks.
Second half-hour—Five-minute poses. Start with the same landmarks, but add more volume and contour.
Third half hour—Ten and fifteen minute poses. Add more contour; try for complete figure.
For the last three half-hour poses, follow the above steps and then add watercolor and pen, as in the picture at the top.