Many people think that they don't have full control over AdSense earnings.
That is true, but even though you don't have full control over it, you can increase it by a large amount by following few easy steps.
When it comes down to AdSense earning, tweaking and testing means everything.
Without it, you would be literally stuck.
The idea here is to try something, and if it doesn't work, simply try something else until you find perfect solution.
It couldn't be more simple.
So you can test several things.
First thing you should start with is ad placement.
Generally, it's good to have ads somewhere where they are seen.
Don't hide them in your sidebar or somewhere where no one can see them.
Remember, you want others to click on them.
That's the way you earn your money so why should you hide your ads.
Most people say that the most clicks they get if they place large rectangle above the fold.
You can try it yourself and see if it works.
Next thing you can experiment with is ad color.
You can change color of link, description, URL, background and border.
Usually, ad color is based on template color.
Ads should either be in contrast with template or should be blended.
Another interesting thing is that a lot of people put blue links.
They do it because internet surfers are used to clicking on blue hyperlinks so that should be stimulating.
The idea behind this is to simply test.
There are so many possible variation and by testing, you can only increase your earnings.