Future Best Self is a robust positive intervention built on the research of positive psychology and the transformative power of creative expression. Stated simply, Future Best Self aims to increase well-being by helping people craft powerful positive images of their best futures. This paper is presented in three parts: Part 1 (Future Best Self: Who Do You Want to Be When You Grow Up?) is written as the opening chapter of a book for the general public. It provides an introduction to and overview of the Future Best Self intervention. Part 2 (Appendix A – Life Crafting: An Agentic Model of Life Path Selection) offers a position paper describing a new framework for life planning based on recent research in positive psychology. In short, life crafting theory describes how we filter a bevy of internally and externally derived interests – through a process of investigation, imagination, and integration – into a series of intentions aimed at building lives of lasting well-being. Finally, part 3 (Appendix B – Writing Well: The Symbiotic Relationship between Writing and Well-Being) offers a second position paper exploring the extensive connections between writing and well-being. It will show that writing can improve well-being, that well-being can improve writing, and that together they can create a virtuous cycle. Taken together, these three papers draw connections between previously disparate lines of research, offering significant new opportunities for research and application to improve well-being through writing and agentic life planning.