In many university chemistry departments, Graduate Teaching Assistant (GTA) training is a critical part of undergraduate instruction. This workshop is an introduction to TeachLivE, a mixed-reality teaching simulator that can be used to support GTAs who facilitate active learning. Simulated classroom environments are a powerful training enhancement because they can provide a low-risk rehearsal opportunity for GTAs to practice evidence-based teaching skills before trying them on actual students in their classroom. Over the past two years, chemistry GTAs have used the simulator to practice calling on students & responding to incorrect answers, asking questions, and facilitating groupwork. These skills were chosen to encourage student participation and increase the diversity of voices represented during class. The facilitators of this workshop have found measurable impacts of GTA participation in the simulator including an increase in student-centered instruction after four simulator sessions. In this workshop, an introduction to the technology and description of how to design a chemistry module will be presented. The simulator will be demoed, and participants will have the opportunity to interact with the student avatars, if desired. Participants will then work in small groups through a planning worksheet that guides the module development process allowing for customization in different contexts. The session will end in an extensive Q&A session to ensure participants leave with a clear understanding on how the technology can be implemented at their institution.