Most leadership programs emphasize knowledge over skills, being skillful over how to be skillful, knowledge about skills over skill application, and ad hoc and hard-to-assess field activities over focused and observable skill practice. "Knowledge and skill application laboratories" provide opportunities to experiment with--and receive criteria-based feedback from multiple observers on--new ways of thinking and behaving. They challenge students to integrate course-specific content with universally applicable skills: diagnosis, goal setting, communication, teamwork, and conflict management. We describe the purpose, history, and objectives of this kind of laboratory, sample lab activities, design considerations, and what we learned. (Contains 2 figures and 6 tables.)