Freehand sketching is the quickest way of getting your initial designs on paper before an idea is forgotten. Freehand sketches are often done without a ruler or template and instead are produced quickly and freely. They can be shown in 2D or 3D. 3D drawings encourage the designer to consider what the product looks like from different angles and whether or not they need to adapt or change their ideas.
Annotation can be added at any point to show key parts, sizes, materials, components and construction. The use of shading, colour and different viewpoints can be an easy way of communicating initial ideas.
Formal hand drawings would use tools such as rulers and set squares to ensure accuracy and neatness. Using computer aided design (CAD) allows the user to quickly make changes, and the drawings can be digitally shared and copied with ease. Formal drawings are used when showing an idea to a client, showing measurements or getting feedback from a user group.