One of the most fundamental, if not the fundamental, decision in object design is deciding where to put responsibilities. I’ve been working with objects for more than a decade, but I still never get it right the first time. That used to bother me, but now I realize that I can use refactoring to change my mind in these cases.
Often I can resolve these problems simply by using Move Method (142) and Move Field (146) to move the behavior around. If I need to use both, I prefer to use Move Field (146) first and then Move Method (142).