Try blending your ads with the template of your blog, put your ads at the top left of the page and drive traffic to your blog because high visitors=high earnings
You would want to have great content optimized with researched keywords you can dominate, and also build as many backlinks from authority sites as you can. This should help drive traffic to your site if you haven't done so already. You might also want to experiment with different ad positioning.
Create value. Make sure your sites visitors intentions match the advertisements being displayed. That's the real key. Placement, colors, all of that is only part of it. People will only click when they see something that matches their reasons for visiting.