Some design guidelines from Google

• Make a site with a clear hierarchy and text links. Every page should be reachable from at least one static text link.

• Offer a site map to your users with links that point to the important parts of your site. If the site map has an extremely large number of links, you may want to break the site map into multiple pages.

• Keep the links on a given page to a reasonable number.

• Create a useful, information-rich site, and write pages that clearly and accurately describe your content.

• Think about the words users would type to find your pages, and make sure that your site actually includes those words within it.

• Try to use text instead of images to display important names, content, or links. The Google crawler doesn't recognize text contained in images. If you must use images for textual content, consider using the "ALT" attribute to include a few words of descriptive text.

• Make sure that your <title> elements and ALT attributes are descriptive and accurate.

• Check for broken links and correct HTML.

• If you decide to use dynamic pages (i.e., the URL contains a "?" character), be aware that not every search engine spider crawls dynamic pages as well as static pages. It helps to keep the parameters short and the number of them few.

 

What next?

Because search engines base their judgement of what is unique on the content of the page, the order in which duplicates were discovered, and volume and quality of links and citations, Greenlight’s Bunn advises that the best way to insulate against any future steps search engines may take against duplicate content is for sites to ensure their pages:

• have a sufficient amount of original text content, supported by images, videos and other multimedia as appropriate.
• are rapidly indexed by the search engines.  To achieve this the site should be regularly linked to, necessitating some kind of link acquisition strategy, and new pages should be submitted to the engines via XML sitemaps and featured on the homepage or another highly authoritative hub page in the respective site (such as a category homepage) until they have been indexed.  If the site has a blog, make sure it pings the search engines when a new post is published (most do), and then use the blog to publish or link to new content on the site.
• are linked to and/or cited directly by third party sites.  Since it is rarely practical or economical to actively link build for every page in a site, consideration should be given regularly as to why someone/a third party would naturally link to the site’s pages or share them on Twitter, for example.  If a firm/site cannot think of a good reason, it may need to go back to the drawing board.

“This problem (low value and duplicate content) is one of such perpetual nature that the search engines are sure to revisit it again in the future.”