Inspired by Theodore Schatzki's "societist" approach--in which he advocates a notion of "site ontologies"--in this article, we outline our theory of practice architectures (a theory about what practices are composed of) and ecologies of practices (how practices relate to one another). Drawing on case studies of four Australian primary schools, we examine how practices of leading relate to other educational practices: professional learning, teaching, student learning, and researching and reflecting. We find "leading" not only in the work of principals and other formal leadership positions, but also in the activities of teachers and students. We show that changing leading practices requires changing more than the professional practice knowledge of individuals; it also requires changing the practice architectures (cultural-discursive, material-economic and social-political arrangements) in sites where leading and its interconnected practices are conducted. In order to study practices of leading, we adopt a "philosophical-empirical enquiry approach," i.e. we conduct our research as a conversation between practice philosophy and theory and the empirical cases of leading we study. We study practices in the mode of "research within practice traditions," sometimes described as "practical philosophy," as a contribution to the self-reflective transformation of the practices we are studying.