1-The first rule is “DO NOT TRY TO CHEAT ADSENSE” by abuse clicking. Adsense has very talented engineers and have a very developed system to detect such clicks and misuses. The more you are reliable the more Adsense supports you.
2-People are curious about your content not about sidebars or your headers, so if you embed your Adsense Ads. into your contents your readers will notice them very easily.
3-Make your Ads. suitable with your web pages (adjust colors of border, font.. ec. )
4-Don’t think you will make more profit when you put your Ads. all over your pages. People are conscious about unnecessary Ads. and they may be bored of these Ads. If you put too many Ads. they don’t want to visit your site again.
5-If your web site is formed from tables, do not put your Ads. into another table different from your content. Because google bot couldn’t associate your Ads. with your content if it couldn’t find your content to search.
6-Investigate your script and delete robot.txt file from your ftp or put pages into your robots.txt file which you don’t want bots search in.
7-Make your web site plain and do not disturb your visitors with unnecessary eye-tiring pop-ups, banners or Ads.
8-Use sitemaps and rss files to make bots search and index your web site.