To make money from Google Adsense, you need to work on two aspects: 1. The traffic of your websites. The measure is the impression. This varies site from site. It is very difficult to copy others. 2. Ad placement. The measure is the clickthrough rate (CTR). This is independent of the website content. You can learn from other websites easily. I summarized my experience in this article. http://forum.abacin.com/post/435/How-to-increase-the-clickthrough-rate-CTR- After those measures, my CTR jumps from 0.2% to 1.5-2%.
That's exactly what I think. Also as a third point I'd recommend: 3. Target non technical audience, like women or common people. Techies are the hardest audience to get to click on ads, especially the webmasters/bloggers.
I also think that the target market plays a big role in the amount clicks you get. Aside from ad placement, and traffic, like senserly said, a non techie user is more likely to get your more clicks.