Write what you want to write
When I finally got to work writing on my novel, no advice helped me more than this: write what you actually want to write.
This might sound a little silly, or even self-indulgent, but what I mean is-- if you've been having problems being able to pull a narrative together, no matter how much prep work or plotting or certainty about your vision that you have, take a step back. Asses what you're actually doing versus what you think you're doing.
To use myself as an example (because that's the one I have), I spent my whole life thinking I wanted to write fantasy stories. I used to read them voraciously as a kid, and really love indulging in conversations about metaphysics and fantastical logistics. I spent over a decade circling a fantasy universe -- magic system, creatures, cultures, fantastical geography -- in service to a story that's been percolating in my head for even longer.
But every time I sat down and tried to actually write, something would fall apart, and I couldn't quite figure out why. I had false start upon false start, sometimes making some decent headway but always the ground would collapse from under me. It wasn't an issue with the characters, or the plot, or the setting-- everything worked, everything was internally coherent, but for some reason the piece simply refused to click.
It wasn't an easy fix, either, because when I went in to really drill down on the issue it was an innate dissonance, a feeling of everything coming apart at the seams even though everything should have worked. I took an extended break from that work, went about my regular adult life, and then finally came back to this project with a new eye-- not for what I wanted to do, but what I had been doing.
And that was when I realized my problem. This entire time, I had been trying to stretch a high fantasy epic over writing that longed to be a horror story.
Which was always where the narrative collapsed, one way or another, under its own weight-- the big fantasy setpiece was a cosmic horror fever dream, the characters were wrestling with existential dread more than they were monsters, the whole quest was building up to a reality-warping outer god. Of course it was a horror story, but my dumb ass was so deep in wanting to live up to all those fantasy books that had so inspired me I had completely missed my own genre drift.
Once I recognized that and pivoted into that narrative, everything fell into place. Needed some amount of its own development, but so much of the structure was already there, it just needed to understand its true shape.
If you've been struggling with a story despite having done everything right-- if something about it is just failing to come together and no matter how much plot analysis or character reworking you do it never seems like it's enough-- it might be that you're fighting your own instincts and what you think you want to write isn't necessarily what you want to write.
There's no easy fix for this except trying to step back and assess it from a third-party perspective. Try showing somebody you're work and asking them what genre they think you're writing for, without telling them what you're going for. It can be a little frustrating to realize this dissonance, especially if you really felt like you were dedicated to this idea. But it can also be freeing, and nothing feels quite as good as being able to feel that friction finally melt away and make way for what you actually want to do.
And the development and work you already did doesn't have to be for naught. You can still incorporate those ideas and characters; those are with you for a reason, and you might find that they fit your clarified vision even better.
