Getting the outline right

This model I drew at a workshop in West London, England. She grew larger each time she posed. She is Brazilian and with her partner was saving up to buy a home in Brazil. I had only just begun life-drawing, and found in this session just how slow using a pencil is compared with Conte pastel. With Conte, which is a stick of solid medium, you can shade with the broad side, filling swathes of paper at a stroke. With your sharpened tip, you can pick out line and detail. But with a pencil, you just have your sharpened tip and nothing else. The shading you have to do by cross-hatching, something I had not learned then, and still have not studied.
You can see that I was obsessive about getting the outline, a characteristic I can't shake off. I wanted to express the image in a single outline before I did any other work on it. Wrong! You can do just as well by first drawing only the shading, and detailing outlines later. Here, I have not learned more than a French or Spanish cave-painter two-hundred and seventy centuries ago.