Ask HN: How do you organize your thoughts about an important decision?

If you are facing a difficult decision in life, such as whether to buy a house or take a certain job, how do you organize your thoughts? The result of a decision for these examples will affect your life in many different significant ways; so many, in fact, that it's unlikely you can consider it all at one time. Do you have a way to organize your thoughts to make a more insightful decision in these situations?