At any point in a project, you can find me sketching out context maps, initial thoughts, user flows, and interfaces.
They're a useful tool in the beginning stages of design before taking it to wireframes or full production. Sketches serve to get the design concept on paper and into the discussion as soon as possible. They allow for rapid revisions, moving the team and the concept to the right design swiftly.
All sketches done for various contextual models and concepting.