A key part of keeping doctoral and postdoctoral trainees in STEM research careers is mentoring. Our previous research indicates that mentoring trainees in scientific communication (SC) skill development increases research career intention through two social-cognitive constructs, self-efficacy in and outcome expectations for acquiring SC skills, as well as science identity. While many mentor training interventions exist, no programs focus on developing SC skills specifically. The "Scientific Communication Advances Research Excellence" (SCOARE) program trains mentors to address trainee scientific communication (SC) skill development as an innovative approach to increase trainee research career persistence. The SCOARE training is a half-day workshop for faculty mentors of research trainees at five sites nationally. Informed by previous research, workshop content focuses on practical, effective mentoring strategies to develop trainee speaking and writing skills. Anonymous evaluation data collected after each workshop indicates participant satisfaction and reported positive increases in skills and knowledge in applying new and various techniques when mentoring trainees (skills) and how linguistic bias influences our perception of others (knowledge). This article outlines the research-based development of the SCOARE program, the first two years' of workshop evaluations showing positive increases in skills and knowledge, and lessons learned to increase participant satisfaction with the program.