Design Optimization- Keep it Simple and Valid (KISV)
Simple design with rich content is always the key to SEO. In addition, redesigning a webpage for SEO purposes is no easy task especially when you have to strike a balance between the original design and SERP (Search Engine Result Page). Start simple and have it validated to achieve the best results.
Pure web design
A good web page design do not necessary need to include massive JavaScripts and Flash plugins. Bear in mind that these codes reduce the Text to Code Ratio and add onto the burden of indexing. The most important designing element is to make sure that the navigation system is readable by the Search Engine. You can achieve this by using text links for internal pages.
Validate your pages
It is a good practise to always have your webpages validated. Search Engine may not index your page probably if it contains errors. Therefore, always have your HTML page validated by W3C using their validator. It will also increase the trust of your page if visitors know that your site is verified and validated by W3C.