Conversion optimization is really about influence. You are influencing people to convert. You are understanding how the mind works. In order to become better at CRO you need to learn from the master of influence and psychology, Robert Cialdini.
How to Apply Cialdini’s Six Principles of Influence to Your Website (http://www.jeremysaid.com/how-to-apply-cialdinis-six-principles-of-influence-for-cro/)