It's such a small piece of code that it's easier and more efficient to deliver in an email message. Simple and Intuitive Site Navigation. Make use of the ALT tag - it's there for a reason. Also, give your users a couple of ways to navigate your site. And make sure your navigation scheme works on ALL of your pages.
Consistency is Key.
You don't want to confuse your reader. Consistency will make it easier for your users to find what they want on your site. Use White Space Effectively. Again, this goes back to the KISS principle. Use your screen real estate effectively.