As our eye moves from one image to the next, ... constancy in design allows viewers to focus on changes in information rather than changes in graphical composition. A steady canvas makes for a clearer picture. – Edward Tufte
Non-technical graphics can be used to provide visual interest in the manual. Graphics should relate to and reinforce the theme of the text.
Many kinds of graphics can be obtained from clip-art or click-art sources. When using existing artwork, try and use graphics created in a similar style.
More complex graphics, or graphics on specific subjects, can be custom-developed by graphic artists either manually or using a graphics computer program.