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.
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.