Here's a drawing from Monday's life class:
Click any image for a larger size.
We had two 40 minute sessions with this pose. I worked on the above drawing for about half an hour. This was preceded by several studies I made of the pose in an attempt to work out the proportions and perspective:
Studies like these were drawn quite quick (5 or 6 mins), while others were scribbled out in barely over a minute:
I used each drawing to study different aspects of the pose.