Regardless of if its printed materials or a website design, these truths are valid.
1. Break up long passages of text with headers.
Readers skim pages, use headers like newspaper headlines to draw a reader into your message.
2. Keep your line lengths short.
Full width text passages make it difficult to pick up the next line. Studies have shown the best line length for text is 50 - 80 characters wide for best readability.
3. Don't use all caps.
All caps are difficult enough to read in print and even more difficult on a monitor. Our eyes are trained to recognize word shapes, and all caps slows down shape recognition.
4. Include "white space" and use short paragraphs.
White space means open areas of the page without graphics or text. Lack of white space creates visual clutter. Short paragraphs are easier on the eye and help you to more effectively convey your intended message.
5. Don't center text.
You can center headlines, but ideally text should be justified. The most common use is left justified text.
6. Don't reverse text.
Reversed text produces five times the eye strain. It literally screams don't read me to your audience. It can be effective in headers or as a way to break up passages. But it should always be used sparingly.
7. For the web keep page sizes small.
In print this one is not important, but on the web it is vital. Keeping content as efficient as possible keeps your pages loading fast. Users will not wait around long.
8. Minimize animation.
It's visual noise and slows pages down. If you have to use it, do so to help illustrate your communication, not to be cute.
9. Keep your graphics sizes down.
Graphics should compliment, not overwhelm a page. An exception is when the graphic is the subject. Users will wait for it to load if it is the object of their interest.
10. Be careful with background images.
Most background images are too "busy" and interfere with your message. If background images are used they should be very subtle and help to support the page not hinder readership.
11. Use colors that compliment each other and provide enough contrast between the text and background that it's easy to read.
12. Spell check pages and proof read all of your copy.
Spell checking catches misspelled words. Proofreading catches other mistakes that spell checking misses.
13. Keep out unnecessary design items.
One of the main tenants of the security industry is, "Need to Know." If you need the combination to the safe, you get the combination; if not, you don't. For communication design the operative phrase is, "Need to Use." Do you really need to use that design element? Does it assist your communication? If someone came in and removed an element, would the page be any less understandable?
14. Keep a consistent navigation structure.
Make it easy to go back and forth between pages and between content areas. Visitors will be more inclined to explore your site if they don't get lost.
15. Keep a consistent look from page to page.
Changing the background on every page may be OK for your personal web site, but on a business site it shouts amateur and has a negative effect on your credibility.