Blending, Ad Location, Content Integration, Separate accounts, and Avoid Using Standard Banner ads.
Blending: Try and make the ads as transparent as possible. Make the ads look like they are part of your site. Use the same background, title colors, etc – it can result in a higher CTR (Click Through Rate) and therefore having the chance to make more money. Google does a pretty good job at providing you with the tools to customize the ads to match your site right off the bat; however, you can customize them even more provided you know some basic HTML/CSS.
Location: Is very important! Place your ads in places where people can and will see them. The higher up on the page, the better (above the fold).
Content Integration: Incorporate the ads within your blog posts – if you have video and/or images use them along with the ads.
Create separate accounts: if necessary. This is a tip most people aren’t aware of. If you have multiple sites and use one adSense account for all your sites (which you can), and, if one of your sites has an extremely low CTR and your other site has a high CTR it will hurt your earnings. If you must create a separate account (with a different identity – just make sure it’s real!) for the site with a poor CTR. As an alternative, try removing ads from your low CTR site and analyze your earnings.
Don’t use banner ads exclusively. Banner ads have been around forever, people know them and most importantly of all people hate them. I’m not saying don’t use them, however, skyscraper ads, rectangle ads, square ads and specially text ads, tend to work better.
These simple but effective tips will enhance greatly your revenue potential for AdSense. And remember, do not click on your own ads. If you get caught (and you will), Google will ban your account and you will loose all the earnings you have made. Happy AdSensing:)