So I decided to try traditional for a change and bought watercolors and nu pastels. My experiments with the former were a complete failure, rendering some brushes really ugly, some paper really wet and some shirt really stained. But the latter was more forgiving, and having watched Mark English draw the figure I decided to try his way. Below are the quick drawings done.

Pastel Study from reference 1 Pastel Study from reference 2 Pastel Study from reference 3