Here’s a writing tip to test out: Write the last chapter early on. You might even write the final chapter first.
I’ve heard from dozens of writers who do this, and there’s a lot to be said for playing with the technique. I almost always have the final chapter written before I’m halfway through with a book. Several times (including with Molly Fyde books), I wrote the epilogue before I wrote the prologue.
This doesn’t mean you’re locked into that chapter. You can change the ending later. Maybe it’ll be different characters. None of that matters. What matters is that you have a sense of what your book is about, what the great climax or resolution is all about, so you know what needs to happen to get you there.
It’s also like a line in the sand. A target. Something to aim for. If you set off on a walk, and you don’t know how far you’re gonna walk, you don’t know how to pace yourself. You might not even want to set out, because the journey feels interminable. Last chapters are also just plain fun to write. Give it a try. And then go back to the start, connect those two dots, and you’ve got yourself a story.