Hi,

The Australian AdSense team has put together a step-by-step guide to optimising your AdSense performance. They cover:

1. Analysing your webpage
2. Creating custom channels
3. Determining best ad design and placement
4. Maximising ad units on a page
5. Tracking and measuring your results

Keep in mind these are the best practice advice from adsense australian team but results may vary site to site. You have to try the adsense units best suit to your website design and don't forget to use channel for each of the unit. After trying for few days or month try to remove low CTR ad units and try to replace it with best performing ad unit. Also don't forget to use Image Ads with Text ads mainly for 300X250 and 160X600 Units. As Banner ads have 50% market for all Advertising Market on Internet.

So Try it... Test it....Get the Best