Choices lead to more choices, which lead to more choices. A decision tree can be helpful when decisions along the tree are simple and predictable, like yes or no. They are a way to think ahead, and lay out the choices you are likely to face, based on decisions you make today.
How to do it: Start with a question and then add potential decisions and outcomes. What are the choices you must make first? And for each choice, think ahead to the next decision. What will your choices be at that point? Keep going and define the paths and decisions until you reach an end point or a point beyond which there are too many uncertainties.
If you decide to go back to school, for example, then you will need to pick your major and courses, and you may need to quit your job. If you quit your job, you may have to live more frugally, and so on.
Are you facing a major decision in your life or work? Can you make a decision tree to think ahead and predict the choices and paths available to you, and where they might lead?