So why keep a sketchbook?
Well, because it makes your creative work more reality grounded!
Even though this quick portrait might seem unrealistic, it is based of a sketch I did of a waiter. He had quite a unique chin really tucked in to the lower part of his face. It seemed especially small because he had a large forehead contrasting it.
You can see my sketchbook sketches on my other blog: The Daily Sketchbook
Here is the sketch inspired by one of the drawings: