Optimization of Adsense

I need someone to optimize and make changes to my adsense account. over the last 12 months my account cpc ws gwing and reached approx 65 cents per click, then i made some changes with a freelancer who did some setup OF the DFP which killed my clicks and CPC. I had another person do a job which my clicks began to improve again however my CPC has continued down and is approx 20 cents. I need someone to optimize and make changes to adsense and or DFP to increase my cpc and any other recommendations.