1. Banner blindness applies to navigation too – avoid images in nav bars, and make sure linking boxes are mostly text and are similar in design to other nav items. Putting similar products/upsells/accessories on the right makes for instant banner blindness.
  2. Make sure your navigation caters for deep linking – one good method is to start by designing the navigation on lower-level pages.
  3. Keep your main menu in secure areas (checkout, etc) – don’t remove it (if customers want to leave, removing the nav won’t stop them), but do change the design slightly to reassure customers that it is a different part of the site.
  4. Don’t use horizontal drop-downs from your top nav (unless they’re wide “mega-dropdowns”) – they take too much motor skill for almost anyone.
  5. To avoid “filler copy”, don’t put children in the sidebar – ie don’t list a page’s subpages in the left-hand navigation. People often miss them and get stuck, and it means you often have nothing worthwhile to put in the page body. The left-hand nav is for the page’s siblings (the pages on the same level in the sitemap).
  6. Indicate clearly which section a user is in – rely on size and bold more than colour, as many people are colour blind to some extent.
  7. Always provide an alternative to flash navigation – eg if you have a Flash filmstrip of product types, provide normal links as well (a mega-footer is good for this)