Because figures and tables can now be created by just a few keystrokes, it is tempting to swamp the reader with them or get caught up so much in bells and whistles that fundamentals are ignored. Some papers include oversized three-dimensional objects to display one-dimensional data, the illogical use of a different color to represent each data point, or fancy fonts and special effects that dazzle the eye but confuse the mind. Just as commonly, there is a lack of elemental detail or care: Xeroxed figures or tables from a textbook with the original (and therefore inaccurate) page numbers not even whited out; a figure whose caption is simply "Costs"; undefined terms, unlabeled axes, uncited data. The list could go on for too long.
Yet these errors are just as easily avoided as committed, especially if you only use figures and tables when it is appropriate to do so. Tables and figures are supposed to be designed to simplify and condense the presentation of what is otherwise complex information. Their function is to save the reader time, enhance comprehension, and allow rapid comparison and interpretation of relationships or trends. Remember this as you prepare figures and tables, and present them accordingly. Further, understand the inherent problems associated with data sets that are either too large or too small, the need for proper scale, both the pitfalls and value of color, and that good graphics are purposed to make sense of data, not vice versa.
Excellent discussions of figure and table basics await you at these sites: