How quick can you be and still produce something vaguely human? We had about ten minutes to do each of these A1 sheets of newsprint from a live model using brush and ink. What they lost in accuracy they may possibly have gained in fluency.
The top one has two reasonable images followed by a really bad one, with rubbish head and shoulders, on the right hand side. No time to make corrections.
The lower one showed the consequences of doing what we were told: overlapping the images to explore space in the picture plane. A very useful exercise even if a very uneven result.