Nobody pours concrete without a blueprint. Sketch the plan before you start pouring years into it.

Effort hardens. Once you have spent three years on something, the cost of changing direction includes all of it, which is why a little thought at the start is worth an enormous amount later. Most people plan carefully for a weekend trip and then drift into decisions that occupy a decade.

Write one page about the next few years before committing to them. What you want it to produce, what you are trading for it, what would tell you it is not working. Keep it short enough to reread, because a written plan makes a wrong turn visible while it is still cheap.