Zen to Done (ZTD) is a productivity system created by Leo Babauta that helps individuals build individual habits, step by step, as they work through a workflow management system. The system suggests forming 10 productivity-boosting habits, but Babauta recommends starting with four core habits: Collect, Process, Plan, and Do. These habits focus on documenting to-dos (Collect), reviewing and prioritizing tasks daily (Process), scheduling time for high-priority tasks (Plan), and minimizing distractions while working on big rocks (Do). By mastering one habit at a time and taking a step-by-step approach, individuals can develop the willpower needed to implement significant changes in their workflow.