Constructing an Iris, Shapes and Negative Shapes

Iris flowers are complex, folded, curling masses of twisted petals and sepals. How do you approach drawing something with so many curling and overlapping layers? The secret is to lay out the structure and then use shapes and negative shapes. Close one eye and flatten the 3D image to interlocking 2D shapes. Click on the first image to start a step-by-step slide show.