High contrast (e.g. dark text and light background)
Beware of large blocks of bright colors
Beware of dark or patterned backgrounds
Gradient backgrounds sometimes don't print well
Use color to emphasize/differentiate/add interest (not just because they're there)
Font
Large enough to see from at least 5-8 feet, e.g. 14 (if printed at 200%) for text, larger for section headings and even larger for title (to be seen from 15-20 feet)
Simple font (e.g. Arial)
Italic and bold work better for emphasis than underlining
Keep to one (or very few) font types
Minimize use of all caps
Graphs/Pictures
Should be understandable, readable, relevant
Follow basic guidelines for statistical graphics
Beware of clipart (use when it clarifies, illustrates)
Use appropriate resolution for images/photos
Minimize use of multitudes of numbers—use graphs whenever possible
Jpg files are usually more efficient than other types for images
Images and objects should be inserted, not copy/paste