Basic shape manipulation will allow for a deeper understanding of your references as well as allows you to manipulate your reference in more creative ways. By developing this skill you are building Spatial awareness. This is key to being able to draw from imagination.
Covering basic shapes, Core Shapes, rotating planes, rotating polygons, Combining core shapes, subtraction of simple forms, and shearing of simple forms.
With a solid understanding of how to manipulate spheres, cubes, cylinders, cones, and pyramids you will be ready to draw and express yourself.