1. Use channels. Create channels for different locations on your site such as 'sidebar' and 'footer.' Place each ad into a separate channel so you can compare the performance. Anytime you make a change to an ad, make a new channel for it so you can compare the new and old performance.
2. Use the 336x280 Large Rectangle, 300x250 Medium Rectangle, and the 160x600 Wide Skyscraper formats. According to Google, these are the most effective ad formats.
3. Optimize the color palettes of your ads. This can be accomplished by blending or contrasting. Blending would make your ads use the same colors as your site, making them more attractive to your visitors. Contrasting would make your ads use opposite colors, making them stand out to your visitors. Each method can be effective so experiment using channels to find out which works best for you.
4. Use image ads. When creating a new ad, make sure you select 'text and image' to rotate between the two. This will allow Google to display the most effective ads on your site.
5. Place your ads in the optimal locations. Google has done the research for you and found out what the best locations to place ads are. Check the resources section for more information.
6. Use customized search through Google. When a user uses your customized search bar, Google will display ads to them based on what they were searching for. This grants you an additional revenue stream. This is especially useful if your site has a lot of information users might need to search for. Take full advantage.
7. Experiment with the location, colors and formats of your ads. You can track the performance with channels and always change them back. Ads you create with Google Adsense are never deleted.