This guide was developed from recently conducted research on the importance of structured support in STEM PhD programs. The project, led by Drs. Ben Zwickl & Mike Verostek, highlights the challenges students face — whether they are exploring their research interests or solidifying their choices — and emphasizes the need for departments to build structures that address both interest development and social networks. The guide provides actionable strategies for creating environments where students feel empowered and supported in finding the right fit, both academically and personally.