For me, this approach works great with one enormous exception: I must already know exactly what I'm going to write about.

I have tried outlining my writing countless times. But inevitably, the real work of thinking meticulously comes with the writing itself. In composing prose at the finest level of detail, I discover the true shape of the topic through its nuance.

I always throw out my outlines, no matter how many times I have iterated on them. My high level thinking couldn't sufficiently understand the topic.

PG expressed this well: writing is thinking, at least for some of us.