Writing is a puzzle, but a three-dimensional puzzle, like a puzzle box.
A well-crafted story has a conflict and actions that lead to a resolution at its most basic plot. But there are layers, extra dimensions, and also subplots that deepen a story and draw readers in. The trick is to give away just enough to spark questions in the readers' minds without giving away the idea, then lead the readers on the journey.
Every step of the story should inspire readers with questions of what COULD happen next.
That can be one of the most difficult parts of the craft of writing. But what happens when the puzzle pieces don't fit? I don't usually focus on the technical until something isn't working and I can't quite put my finger on it. That's when it's time to walk away and do something else for a while.
Think of it this way--corn starch and water aka oobleck. Put pressure on it, and it solidifies, becomes impenetrable. Release the pressure and it flows.
Sometimes creativity is like an oobleck. We push and push and it's like our creativity freezes. Then, we put it aside and at some point--poof!--the answer comes without effort.
When I finally sat down to write, it all came together, FINALLY! Now, it all makes sense, and those extra layers of the story all tie together the way they were meant to. And what is resolved at the end is sparked early on in a way that will create the right questions to lead readers to what comes next.
Persistence pays off, but so too does knowing when to step back and take a break.