Reflexive monitoring is a method developed to monitor and evaluate transformative solutions. It is based on transition theory and helps you to navigate the complex and unpredictable nature of non-linear and multi- actor processes. It will prove very useful for the implementation of large-scale nature-based solutions. It will help you to break through barriers that you encounter, split up your work into manageable actions, and stay connected to the long-term goals of your project. This guidebook offers a practical approach and tool-box for setting-up and applying reflexive monitoring. It will help practitioners to deepen their understanding of reflexive monitoring’s methodology.