June 2017 — A growing international evidence base across a wide range of disciplines points to the central importance of soft and life skills for empowering youth to flourish and achieve their goals. Despite frequent calls to focus programming and research on soft skills, little attention has been placed on understanding how these skills are built and what practitioners should do to foster them. This report fills the gap by identifying six guiding principles for effective skill-building programs. Findings drew from literature reviews, meta-analyses and general guides on how to develop soft skills. The report provides specific examples of effective practice applying each principle, citing international and U.S. youth programs across the fields of workforce development, violence prevention, and sexual and reproductive health.