oClean URL structure:

Dynamic URLs and season IDs in URL are not good so the developer need to use a unique PHPSESSID variable. If the season IDs will be included in URLs so, the search engines will treat a single page with different season IDs as different pages. It leads to duplicate content which is punishable by search engines.

Use keyword rich permalinks with url_rewriter tags, which makes the URLs friendly for both search engines and visitors. Also decrease the use of special characters other than the hyphen (-) symbol.

oAvoid canonical errors:

Search engines treat www and non-www sites differently if also they contain the same content. Duplicate content issue may arise, so use 301 redirection. In this concern the PHP developers need to spend more time on the homepage as the site.com/index.php will be treated as different to site.com.

oPutting right heading and bold tags:

Optimizing the website for search engines in the development period carries a lot of responsibilities and adds more tasks for the web developers. Creating a dynamic header (header.php) and using unique values for Meta of singular web pages is a must do act for designing an SEO website. So, at the time of coding, using of page-specific PHP variables get’s the work done. $pageTitle, $pageDescription, $pageCanonical, $pageKeywords, $pageRobots, etc are the significant SEO stuffs for On-page optimization of a PHP website. Also, using H1, H2, H3 and <strong> attributes in a webpage improves it’s indexing possibility.

http://hubpages.com/technology/How-to-Develop-an-SEO-Friendly-PHP-Website