A very valuable asset to my arsenal was learning about atmospheric perspective. Perspective alone was not enough to give my work the pop is desires to have.
Atmospheric perspective messes with depth and perspective by means of diminishing detail, hue and saturation the farther back into the background we go. The exercises here allowed me to grasp a method of dividing the proper 'layers' of an image.
This was the point where I moved all my workflow to my iPad Pro and Apple Pencil. I finally transitioned from traditional pencil and paper to full digital in my classes from this point on.