Make sure you put them in good position , colors, etc. The common dolegoas. Don't put them OUT OF PLACE.
Try to put your ads in line with the post on your blog/website, that normally spikes CTR a bit... Put the ads on a place where your visitors often spend time...
You need get more traffic,Wirte attractive articles and rich content, Try to use different advertising style.
optimize your ads for colors and position usually the ad units on top of the site get more clicks rather than footer units
If you don't know much traffic you are getting then go to sitemeter.com or extremetracking.com & get a counter to put on your blogs. At the low end you can expect about 1 click for every 100-200 visitors.