I have been exploring in two minutes what I can do to give a feeling of space. I have been aiming to make the line move and use the same figure to also create and after image and suggest a larger group doing and activity. I feel the first image shown is the best I have done in a two minute drawing. The figure are rested but the lighter line and the slight angled difference suggest being in different areas of the same space. This has been fun to explore.
Also the difference between and heavy tone line and a light line makes them feel more like broken up shapes that fit just right.
This model has made tremendous progress in terms of being comfortable. Simple poses are the best and can suggest a lot. Pentel ink pens are my favorite brand of calligraphy or drawing pens. That is Brush, Needle point, Fine tip or otherwise.
Sometimes if the model is relaxed and comfortable l will just draw them as they are taking a break much more natural.