Epistemic practices are the goal- and norm-guided actions people use to develop knowledge within a domain, such as analyzing evidence to support scientific claims. Developing sound epistemic practices is critical considering the current rise in post-truth discourse that constrains society's abilities to make informed decisions. Learning scientists have increasingly offered frameworks and methodologies to support improved epistemic performance. However, there is a lack of consensus in the field about what epistemic practices are that students can take up, as well as strategies to best support teachers in this endeavor. This symposium brings together seven teams of researchers who have been working on developing epistemic practices in K-12 classrooms. In conversation with each other and the audience, we aim to understand how epistemic growth is conceptualized in its myriad forms across students and teachers in addition to the design characteristics and indicators of growth of learning environments that promote epistemic performance.