Perhaps it's worth sketching out how I approach projects.
While I don't shoot everything that catches my eye, I do quite a bit of random shooting, to no particular purpose. I view this stuff as raw material.
Sometimes a subject will catch my attention. Sometimes a visual effect in some photo editor will catch my attention. Almost anything at any point can "feel like" the germ of an idea that might spread across multiple pictures, but usually it's either a subject or a visual effect.
Then I feel my way forward, is there a good subject for this visual effect? Is there a good visual effect to work with this subject? Sometimes, but by no means all the time, a coherent look coalesces around an idea or a subject. Now I have a set of things to shoot, and an approach to handling them visually, that might ultimately produce a portfolio.
I press on, pursuing this coalesced notion of some pictures I want to make. The idea probably will evolve -- "I love this idea, but it's all so dark and muddy, is there a high-key analog to these theme that would play well?" -- or whatever. A lot of ideas die here, too.
Finally, I get a bunch of pictures, if all has gone well and the idea has survived. Maybe I get 20 pictures, maybe I get 100. Maybe someday I'll get 500. These pictures are first-pass "keepers", they embody the ideas and the look I had in mind, they're on theme, and they're all basically pretty good.
Now I sift through those, and throw a bunch of them out. By now I usually have an idea for a final format, and how many pictures I want, and I want at this point to have a surfeit of those "first pass keepers" so I can cull heavily. I might have to go out and shoot some more. I might have to develop another variation on the concept, to flesh things out and bring balance and interest to the portfolio.
Finally, I have, in a very very small number of cases, a nicely built portfolio of the very best exemplars of some idea, tied together with a set of visual ideas.
This sounds very step-by-step, as if I have a detailed process which I simply follow, perhaps? It's not, though. It's very ad hoc and it's mostly me just following my nose, trying stuff out, backtracking, and throwing out a tremendous number of pictures.