Increasing your AdSense earnings is often about using tactics rather than increasing traffic. Yes, traffic matters a lot; but building traffic is slow and implementing potentially lucrative tactics can happen overnight.
Using the "This Can't Be Related" Image Technique
Images draw the eyes. When people look at a page, the first place their eyes go are the pictures. Then their eyes go to the things near the pictures.
It only makes sense then to put your AdSense ads near pictures. Unfortunately, AdSense is adamant that you can't put ads next to anything that looks related to what advertisers might be selling.
For. example, a giant photo of you smiling while looking at the camera. Make it stylish and classy, then put the ads somewhere near the picture.
It can't possibly be related to the ads, as it's not about a product or even about the content. But it'll still draw the eyes and likely increase CTR.
The Below Quotes Technique
Quotes also draw the eyes. In fact, people will usually read enlarged quotes before reading most areas of the article.
Then put a small AdSense block right under the quote. That quote will get read, people will see your ad and the CTR might shoot through the roof.
The High Contrast Technique
A lot of people say to blend your ads into your layout. But a very effective technique can be to go for high contrast instead.
For example, let's say your site layout is primarily blue. Instead of making your links blue as well to blend in, why not make them bright red to really draw attention to them?
This will really get people to look at your ads. They still might not click, but at least you're getting the views now.
Remember to carefully read the Terms of Service for AdSense to make sure you're not inadvertently violating any clauses. Whenever you experiment with controversial techniques, you really need to be well versed in what's allowed and what's not. Reread the Terms of Service (even if you've already read them a while back) before trying these techniques.