That hard part is not what happens when one finishes a story. It’s getting there first. I have at least two books in limbo right now, started but stopped for various reasons along the way. One I look forward to getting back to, the other I may need to go back to square one. It took me over a decade to finish “Sidestepping Home”, two false starts, and then finally I sat down and finished it over the course of six months.
So what I am doing instead? Rewriting. I have two books that I have the first draft completed. The story is there, spread out over Chapter after chapter. Now I revisit, show it to my writing group (getting another’s feedback is invaluable at times), and sit down with it and rewrite. It helps the story, and hopefully improves it to the point when somebody reads it, they feel satisfied with the money spent buying it (or at the very least, checking it out of the Library).
It’s a process. Sometimes it’s a grind, but like coffee, the better the grind, the better the flavor.