Computer Aided Design (CAD) is a nice tool. Many people feel that it, along with email and other electronic transfers, have increased designers' productivity. Hmmm...not really. Just as the invention of the washing machine didn't shorten the amount of time cleaning clothes (we just bought more so it was still an all day chore at best), computers have done nothing to shorten the design cycle. Sure, clients just make more changes to fill up those idle hours, but the biggest reason is that design is not done on computers. It is done in one's head. My design process is to take all the constraints, all the requirements, and the budget and think. And think some more. When I see something in my head I copy the image to a sketch pad, evaluate it and either continue refining it or turn the page. The quickest way to do this is with a pen or pencil and your choice of hands. One doesn't have to be a illustrator. You just have to transfer your idea to the client. I've known some designers who are not technically "good" at sketching, but they have developed a craft of quick rendering after lots of practice. Which is really what design sketching is: it is a craft that can be learned. It is not art. It is language. Here is a sample of some of the quick sketches pulled from my many sketch books--and maybe one or two CAD drawings that break the rules.