User Experience Principles:

• The function of every element on the page should be as obvious as possible.
• Expect users to skim, satisfice, and muddle through pages.
• Use a clear visual hierarchy to help users find things faster.
• Don't go against conventions unless your change brings a significant and easy-to-learn improvement.
• Assume that every element is visual noise.

Navigation Design:

• Use navigation elements not just to show people how to find what they're looking for, but also to give them a sense of where they are and what else the site contains.
• Navigation should be consistently laid out through all the levels of the site, not just the top two.
• Navigation elements (particularly those showing the location of the current page) should stick out.
• Tabs connecting to the pages below are strong navigational elements.

Visual and Content Design:

• All headers and labels should be clearly associated visually with the elements they relate to (framing those elements).
• Make sure that the homepage conveys the big picture. It should tell what the site is about.
• Avoid the Tragedy of the Commons that occurs when too many things are added to the homepage.
• Use taglines rather than mottos next to site logos. (Tell what the site does, not what its ideals are.)

Usability Testing and Improvement:

• Focus groups are for initial planning; usability tests are for iterative improvement.
• Test early, informally, and often.
• Before you have a working prototype, run tests on a couple of sites with similar features or functionality to get a sense of what works well about them.

Accessibility Considerations:

• Be considerate of the user. Try to have their best interests at heart.
• Several small tweaks in the code can drastically improve accessibility.