Here are the top three tips on how you can optimize your Google AdSense implimentation:

• Lose the colors - you would think that making AdSense stand out would get people to read the text, but you would be wrong. Making AdSense stand out in one way (either significant or not) is a sure-fire way to get people to effectively ignore the ads.
• Blend them in - traditional marketing held that banner advertisements were the way to go when trying to reach an audience on a website, but with the sheer number of banners online nobody ever pays attention to them. So, if you place your AdSense ads in a banner position they're going to get ignored. What you need to do is blend your ads into the content, essentially making the ads a part of the content.
• Test everything - people try to find "the answer" to everything. The truth of the matter is that "the answer" is different for everyone. The same holds true for AdSense: one websites implementation may work great for their audience, but you may need a totally different layout in order to get clicks. Test and track everything: layouts, colors, sizes, etc...

Using these three tricks you should be able to increase your AdSense revenue over time.