Recently, scholars have called for a practice-based framework for teacher education and some have argued more narrowly for a framework built around "core practices of teaching." These efforts, in part, are intended to make teacher education practice public and available for collective improvement. The purpose of this paper is to highlight challenges and possibilities that arose during a core practice-oriented course redesign. Despite attention to the literature, the teacher educators faced dozens of inherent tensions and contextual challenges that distinguish their understanding of core practices from other teacher educators operating with common principles. Based on lessons learned, the author argues for greater attention to the details of core practice redesigns, rationales explaining redesign decisions, and empirical investigation of teacher candidate outcomes of such redesigned courses and programs.