Icons are pictorial representations of functions and objects, important not only for aesthetic reasons as part of the visual identity of a program, but also for utilitarian reasons as shorthand for conveying meaning that users perceive almost instantaneously. Well-designed icons improve the visual communication and strongly impact users' overall impression of visual design. Last but not least, icons are space-saving and improve usability by making programs, objects, and actions easier to identify, learn.
- As a developer use an icon from the predefined set. KDE uses the Oxygen icon set. Ask at the kde-artists mailing list if the set lacks on a specific item.
- As a designer create icons with varying sizes in respect to the level of design. Simply scaling down (or up) does not work.
- Design icons with a small number of metaphors .
- Apply metaphors only once (e.g. do not use a brush twice for different options).
- Rethink conventionally used metaphors (e.g. the clipboard icon of paste).
- Antiquated metaphors might work well (e.g. a floppy is not necessarily outdated to represent save).
- Adjust the degree of abstractness according to familiarity of the metaphor.
- Use arrows only if they can easily be related to spatial features such as Previous/Next in a sequence or Up/Down in a hierarchy. Avoid using arrows metaphorically (such as for Reply/Forward or Undo/Redo).
- Define metaphors independent from language and culture.
- Make icons simple.
- Colorize icons according to the meaning but in respect to application’s colors.
- Don’t use animated icons.
- Test your icon set on strength of association, discriminatory power, conspicuousness, and, if applicable, on accessibility.