Hello in your adsense stats the most important to know and improve is the Page eCPM, that is how much you earn for 1,000 page impression (pages with adsense on it)
eCPM only depends on CTR and CPC.
So you can improve eCPM by increasing CTR (number of clicks for 100 page impressions) it's easy, simply improve your ad placement.
The other side of the problem is increasing CPC, but it is less easy, it involves producing content about high paying topics which advertizers compete a lot by bidding more and more money per click.
But in the end, a very high eCPM is only good if you have a lot of traffic, so increasing your number of page impressions should be a high priority, like number one priority!