This study aims to identify best practices in leadership development in the U.S. to inform leadership development programs in Germany. The study acknowledges limitations in identifying definitive "best practices" due to lack of rigorous program evaluation. However, it strives to identify common principles and patterns based on existing literature and expert interviews. Nine general principles are identified that appear common to effective programs, including reinforcing a supportive culture, ensuring high-level sponsorship, tailoring the program to context, using varied learning methods, and committing to continuous improvement. The study also profiles seven common practices used in individual leader development programs, such as job assignments, action learning, coaching, and networking. Effective approaches to collective leadership development are also reviewed. The implications of trends