Adsense is a revenue collection technique that will serve you better if you keep in mind some very important points. Google itself gave out some secrets of very successful ads that are displayed on adsense sites. I'll be sharing those points with you here.

• Ad Location: The first point to focus on is the location of the ad on your site. The ad must be placed somewhere where the viewers of your website can easily see these ads. Google said that the best performing location was: "the middle, above the fold location perform best." Also if your site contains substantial text articles then the bottom of these articles also give you sweet performance.
• Ad Formats:Here are the top 3 formats as suggested by google:

                        336x280 that you see on the page

                        300x250 medium rectangle

                        160x600 wide skyscraper

• Ad Colors:Try to blend the colors of the ads with the colors of the website. For example if you have a white background, try the ads with white background as well. An example was given where a publisher changed the color to yellow and clicks on his ads dropped by 65%.
• Ad Blindness:If you try different colors with the ads, readers or viewers of the site will instantly know that these are ads and frequent visitors to your sites may not see them at all. Keep changing the format, colors and locations of your ads to avoid total ad blindness on your sites.
• Experiments:This was a theme suggested by many experts. Try different colors, formats, locations for the ads on your website. It was said that you can almost double your revenue by choosing the best color, location or format for the ads placed on your website.
• Focus:Try to keep your focus on the topic of your website. Keep posting backlinks or link units on your website so that even if the user does not find the material he is searching for on your site gets it somewhere else where he may click on ads of his interest.
• Adsense for search:You can place a search box provided from google on your website and must provide google with some place on your website to display those results. Subsequently when ads are clicked you get a percentage of the revenue google earns from the click of those ads.
• DO NOT click on your own ads:Yes, according to google, the chief T&C is not clicking on ones own ads, this may hinder you good performance with adsense.
• Summary:To wind up, always remember your site is unique and is different from others. So not try and keep yourselves limited to the points I have mentioned above. You know your website better than anybody else. So optimization of adsense ads on your site is better know to you than any expert. Just keep the above points in mind while placing ads on your website and keep experimenting till you get better and better results!!!