I really believe one of the main secrets to writing fiction is throwing out the idea that you can neatly plan what you’re doing, and instead allowing yourself to follow the threads as they unspool. You gather them up at the end of the first draft and then knit them together.

Lemme tell you though, I am NOT a pantser. I plan a lot, but I've learned that "planning" is part of writing. It's like a rough rough draft. It changes as I go, and I remind myself to be open to going in totally different directions than I initially "planned."

Does this sound totally nonsensical? That's because it is! Writing doesn't make sense most of the time. You plan and then throw the plans out. You follow a thread and then snip it off in revision. The key is to be willing to change. (For everything really)