Opportunities for teacher candidates to investigate and enact the work of teaching in settings of reduced complexity--what are called "approximations of practice"--offer a promising path toward preparing more ambitious and equitable mathematics teachers. However, these approaches face the risk of not preparing individuals to continue ambitious and equitable practice within the socially- and culturally-defined work they are called to do in schools. In this paper, we discuss findings from ongoing design-based research in secondary mathematics teacher education around considerations for approximations of practice that are more "responsive" to school settings. We discuss analyses of methods courses and concurrent student teaching placements. Two main design considerations have emerged around the way in which approximations of practice are tied to the content and goals of school classrooms and how they specify and explicate the structure and complexity of teaching practice. From these findings, we propose future design and research opportunities.