Cervone, Shadel, Smith, and Fiori (2006) propose that theories of personality architecture may provide an integrative theoretical framework for self-regulation research. Building further on this argument, the present paper considers one comprehensive modern approach to personality architecture, personality systems interactions (PSI) theory. The authors provide a brief overview of PSI theory and discuss a simple, three-step "user's manual" that has guided applications of the theory to real-life behavior. Work on PSI theory highlights some of the integrative potential of personality science in the field of self-regulation. The authors conclude that theories of personality architecture may improve the quality and precision of the counselling, coaching, and training that psychologists in many diverse areas provide. © 2006 International Association for Applied Psychology.