Meaningful learning experiences do not emerge from curriculum alone. They also depend on how we prepare the instructors, respond to feedback, and continuously refine teaching practices. I will share how my work over the past four years at the University of Missouri has focused on designing inquiry-based undergraduate biology learning experiences while simultaneously strengthening the pedagogical preparation and ongoing support of graduate teaching assistants. Using examples from the redesign of BioSci 1500 and the development of a Division of Biological Sciences teaching professional development program for graduate students, I will discuss how student feedback, graduate teaching assistant reflections, and educational scholarship have informed an iterative process of curriculum and instructional improvement.