*In Google Adsense you will find Allow block ads.
*You can go there and see yourself how much each ad category is paying you.
*This will show you different ads category that are showing on your website. If you find that any ad category is not paying much then feel free to block that category.
*Try to block those categories which are completely irrelevant to the content or niche of your blog.
*For example : Suppose blog is about Technology then block the ad categories for Dating, Politics, Religion etc. This will surely increase your AdSense CPC.
Too many ads gives you less CPC.