Throughout my career as a designer, I've always had to come up with ideas rapidly and effectively communicate those ideas to others through hand sketching. This is an invaluable tool for every designer, and one that I often work on.
Below are rough, raw images from my sketchbooks showing the process of rapid concept generation and brainstorming.
2010 - present
Sketching, concept generation
Various sketchbook pages
Sketches for licensor concept pitch (top left), sketches for my business card (bottom left), and additional sketchbook page sketches (right)