Answer: plan
Explanation: I believe that the best thing to do when faced with a large project is to plan. Proper planning helps you to strategize and complete the task at hand effectively. Proper planning includes starting in good time and taking intervals as you split the task into sizable portions so you don't end up overwhelmed.
For example, if you need to bake a cake, you could divide it into baking, icing, decorating and cleanup. So that by the end of the project you would not be tired.