By genuinely increasing your traffic to your site and making sure you have the ads optimally placed so that they are seen and look attractive to the visitors.
Apart from good ad placement, you also need to blend the ads with the background. To figure out the best combination, you may try to use channels.
targeted traffic is the only way to increase clicks! if people find you while looking for something, they are more likely to click on anything that is related to their search. Promote, get quality traffic and post good key word rich content. That is all there is too it. Oh and be patient, it will not happen over months, try many many months!
blend them , even tho i try that and then i get image ads lol and they are totally the wrong colors .. first link in sig for example