This brief outlines five core executive function/self-regulation skills needed for success in life: (1) planning, (2) focus, (3) self-control, (4) awareness, and (5) flexibility. Noting that adolescence is a critical window of opportunity, it offers tips on how practitioners can build these skills, insights into how stress affects the development of core skills, and five ways for programs to deliver services that reduce stress. A companion video is available here: https://developingchild.harvard.edu/resources/video-building-core-capabilities-life/