I mix that in as well.
So, more accurately, what I do is I hit reset 500,000 times until I find terrain that inspires what I want to do. Then, I build a basic shelter to get started while I sit there meditating on the terrain and planning out the basics of what I want, planning out the whole basic idea first, then slowly going though and doing it bit by bit as needed/inspired. Sort of a mix between planned and improvised, mainly so there's flexibility to change the plan if it makes sense to.
Mainly when I do close a world down it's because it's been a while. Usually we will play a world until we get a break or three. Sometimes, that break goes on for too long and when I get that bug to play again, I want to just start over. But it's never been because I feel I built myself into a corner or anything. I definitely always plan out more than I actually build, and it can kind of get overwhelming, but that's never been the reason to start over. Usually I don't regret it, but the last one I really wish I had just continued.
I also like that I learn so much more each time so each time I start over, I'm better equipped to design an even better pack for myself and my friends. This current world is two full months in with steam to spare because of all of the older worlds I've built. This one is going the distance, too.