1 - Make sure the ads that are appearing on your site are closely related with your content. That means the all ads are related to your site.
2 - Use Your main Keyword or theme in the title. Create a keyword-rich content. And you can use keywords in the content 1-3 times and should be bold or underlined.
3 - Always use HTML Heading Tag H1 as your content title of the page and put your keyword in it. This tag should be placed at the beginning of your content.
4 - If your page have some pictures or data using table format then Use wide ads (336×280, 300×250 or 250×250). Because these are the best performing ads.
5 - If your page have more verticles links then you can use links format and should be use border as same as the color of the page.
6 - The back ground of the ads should be same as of the background of the page or pages.
7 - Read and obey the AdSense rules - NEVER click your own ads or ask someone else too.
8 - Filter out irrelevant ads by applying a filter.
9 - Monitor your earnings and performance regularly.