Ok lets accept it that Increasing adsense CPC is everyone's dream :d Here are some of the effective ways that significantly increased adsense CPC . Use Of Leaderboard and Large rectangle ads. Use of new custom size ads increase the adsense CPC significantly e.g if you use a custom Ad size of 750x300 then you increase you adsense cpc for the following reason: Adsense show the highest Bid ad on your site so if it is a wide leaderboard ad it can't show that on a large rectangle so the lower cpc rectangle ad will be shown . The advantage of using 750x300 ad unit is that it can show all sort of ads . It shows the highest cpc ad . Enable both Image and Text Ads (Important) You can disables ad networks in your adsense account . Disable those with lowest Cpc rates. e,g ( Sex related ) and ofcourse use of high cpc keywords that you can find using adwords. But keep one thing in mind that Adsense ads are shown based on the Visitors Search History . So you will have to imaging that what are your visitors upto and then use related keywords.
Home page optimization is the best way of increasing CTR. I know one of my niche website received more than 15% CTR and resulted in a huge adsense earning.
Google Webmaster is a place to start. https://www.google.com/webmasters/ . There's no better trick than Google themselves.
I follow this article which tells to experiment your website using Adsense Heatmap. http://alladsnetwork.com/know-readers-clicking-website/ And there is one more article which tells how to increase your CPC rate overnight. see below link. http://alladsnetwork.com/how-to-increase-your-cpc-overnight/ Hope that helps. Sky.