When things are unpredictable, which is always and which we are basically born to hate, start with an idea of an ideal situation and work your way back, but do it with the knowledge that it will never work out as planned exactly. That things don’t work out as planned is exactly what makes it interesting.
You can try your hardest to make things go as planned, but you’ll undoubtedly change your mind, and how that transpires is always interesting to see. And if you’ve gone into things with the ideal in mind, you should at least be somewhat happy with what transpires, even if, or especially if, they don’t transpire as planned.