This book is about design. Everybody does design, from artists to engineers, from interior designers to industrial designers. We design our days and we design our lives. This book presents the three universal activities that everyone uses, no matter who they are or what they do. These three activities are 1.) clarify an ambiguous project, 2.) generate ideas, and 3.) select one idea for implementation. This book also presents how the psychology of design impacts our effectiveness with each of these three activities, from creativity through decision making, intuition through analysis, and cognitive enhancement through design biases. Although the examples provided in this book primarily target the diverse disciplines of art (painting) and engineering, they can be easily understood and adapted by designers in any discipline. This book helps advanced design students and working professionals in any discipline to understand why and when the basic design principles they were taught work or do not work and, as a result, improve their design effectiveness.