As with any creative endeavor, most of the rules of writing and design (think first, implement second) are broadly applicable. This is the entire process for creating a visualization, more or less.
- Understand your own goals. Are you analyzing or presenting information? Once or in an ongoing way? What does this visual need to achieve? Et cetera.
- Understand the needs, biases, and existing knowledge of your audience (users, customers, investors, etc.); their perspectives are likely different from yours. Your success is measured by their success.
- Only include the necessary information; if it's not helping get the message across, it's noise.
- Define your axes so that placement becomes meaningful. This conveys a huge amount of information with very little ink.
- Consider conventions and standards of your audience and how things occur in the physical world. Follow those conventions when reasonable to do so. Depart from them when you can create a genuinely better format.
- Be consistent with visual encoding, placement, and other recurring visual elements.
- Iterate, test, iterate some more.
- Don't try too hard to be sexy; function first, sexy second.
For more in depth treatments, see my master's thesis, and Beautiful Visualization, below.
Learn more about this topic from Beautiful Visualization.
With contributions from more than two dozen experts, this book demonstrates why visualizations are beautiful not only for their aesthetic design, but also for elegant layers of detail that efficiently generate insight and new understanding. Think of the familiar map of the New York City subway system, or a diagram of the human brain. These older examples have been surpassed artists, designers, commentators, scientists, analysts, statisticians, and others who show how visualizations using today's digital capabilities can help us make sense of the world.