Everyone loves a good story, and I particularly love one if it comes from Pixar Animation Studios. Perhaps that's why I found these 21 rules of a good story (yes, from the Pixar guys themselves) so fascinating. This is rule #7:
Come up with your ending before you figure out your middle. Seriously. Endings are hard, get yours working up front.
This is true not only for a good story, but also for a good strategy. Before you know what or how, figure out why. The way I see it, the ending is "why". Why did we endure this journey? Why did we struggle until the last minute? Why is this all worth it? On the other hand, the middle is "how" and "what". What do to, how to solve a problem, how to follow the path we're supposed to follow to reach our destination.
Good strategies are good stories, and for each new project, first things first. Start with why.