Define the decision.
A useful strategy starts with a choice. Describe what the business is trying to achieve, what is outside the scope and which constraints matter before listing possible initiatives.
Make assumptions explicit
Write down what you know, what you believe and what you still need to learn. Give important assumptions an owner and a review date so that a plan can change when evidence changes.
A useful starting point
Write a short note describing your situation, the question you are trying to answer and the evidence you have. Keep it specific enough that someone else can understand the decision without guessing.