My mileage is all over the place
However, after much experimentation I’ve come back to being firmly in the “narrative first” camp for myself. It’s too easy for me to get sucked into the poetry of a particular piece of writing and then not want to get rid of it even if it doesn’t serve the story, and/or I find I’m just throwing away thousands of words, which is painful.
The conflict corner classes where @JohnDusenberry has described his process of source of conflict → treatment → draft have actually been extremely helpful to me – I think this approximates how I’m naturally inclined to work, although I’m not sure because what I’m doing is more of a second draft than a first.
Ask me again if I ever finish this book and move onto a new one, but I can imagine going forward some kind of process that does more character/setting/worldbuilding work up front without actually writing a draft and then uses the CC process to get to a treatment and see what the actual scenes would look like.