This article will hopefully help you to achieve the maximum click through rate - and earnings - on Google Adsense.
1) Where to put your ads...
On the site that generates the most revenue (its a forum), I place my ads between the logo and navigation links and the main body content.
Remember, Google Adsense allows you to have up to three ad units on one page.
So, if its an article, you could have the ads in the three main sections or at the end of three sections - experiment and see what ad placement works best.
2) Ad colours
Optimizing your ad colours is one of the best way to improve your CTR (click through rate). Make your ads so that they have no border, the background colour is exactly the same as yours, and the text colour is the same as on the page as well.
Remember that if the ad colour picker doesnt have the colour you want to use, you can edit the code with the #XXXXXX colour code.
3) Content of page
Keep the content of the page about one subject and make it full of keywords that are relevant - but dont list keywords, only write good content. Dont use hidden text either. You may want to write a page (or even create a site!), about high paying keywords - this page has a list on the high paying ones: http://keywords.clickhereforit.com/. Also, dont clutter the page, keep the colour scheme the same, keep to the same fonts (Veranda / Arial type fonts work best).
Apply some of the methods here, and be sure to experiment, and hopefully youll notice an improvement in your payments. But remember the golden rule - NEVER CLICK ON YOUR OWN ADS! Good luck!