I would recommend that you think about what area of Psychology that you would like to pursue. Your preference is an important element since it is you probably focusing on areas where you can use your natural talent. Work is never always great, fun, or easy, so being able to enjoy your work even when it is hard is an important component to the choice that you make. Also think about how you see your work impacting the world. You are choosing a job that will impact people's lives. That can be a heavy burden, especially when you are not successful in helping those people.