As a second exercise, I started experimenting with depth through the use of vanishing points, shadows and colors. I found several videos on the internet using vanishing points and spiral shapes. I found Miss Betsy's explanations and examples particularly useful. The technique is not that complicated for the effect you can achieve with it. This is my first step towards more organic shapes and I'm looking forward to experimenting further!
The drawing is made on cold pressed, heavyweight paper. It is partly drawn up with pencil and then filled in with different sizes of fineliners and they are also used for shading. I used three different colors of pencil per spiral, varying the pressure to emphasize the illusion of depth. The dimensions are 28.3 cm by 21 cm (HxW).