Our instructor started off with a quick demonstration, explaining his motions succinctly while he drew: Draw a vertical line representing how large your drawing will be, use a straight edge to estimate the length of the head, use the head as a unit of measurement to determine lengths of other lines.
For example, in skeleton below, the total height is comprised of approximately 7.5 head lengths. Then, I went in further to determine that there are 5 head lengths from the top of the head to the knee joint:
Using this process, I 'boxed in' areas for different parts of the skeleton - such as a box for the rib cage, hips to knees, etc. Once I had an idea of the placement of parts, it was easier to go in and use straight line contouring to get the angles down for each section.
Focusing on negative space is a good tool to fill in areas where the outline of the object is confusing, but where the negative space around it really stands out.
|Used the last few minutes of this pose to focus on negative space drawing|
Here's a skeleton giving a talk that I had a few minutes to box in before class ended: