Sketching is an efficient way to express design ideas without focusing on details or aesthetics. You can sketch on paper, a whiteboard, or a digital device, depending on your preference and availability. To sketch effectively, some basic principles should be followed, such as using simple shapes and symbols to represent the main features and functions. Different levels of detail should be used to show the hierarchy and importance of design elements. Additionally, different types of lines, such as dashed, dotted, or curved, should be used to show boundaries, connections, or movements of components. Annotations, labels, or notes can explain the purpose, function, or specification of design elements. Colors, shading, or textures can highlight or differentiate design elements or show materials, properties, or emotions of the design.