5. Start with what you know; then remove the unknowns.
In design this means “draw what you know.” Start by putting down what you already know and already understand. If you are designing a chair, for example, you know that humans are of predictable height. The seat height, the angle of repose, and the loading requirements can at least be approximated. So draw them. Most students panic when faced with something they do not know and cannot control. Forget about it. Begin at the beginning. Then work on each unknown, solving and removing them one at a time. It is the most important rule of design. In Zen it is expressed as “Be where you are.” It works.