I tend to learn best when I have a definite goal and an opportunity to teach as a learn. Turning my new knowledge into a lesson or an exercise for someone else helps me to sort things out in my own head, and keeps me accountable. This presentation is a detailed overview of a CTF I built and the lessons it taught me. By presenting it, I hope to share some of the things I learn and to pick up suggestions from people who’ve been doing this longer than I have.