Don’t overdo your ending
Don’t go beyond your story’s natural ending e.g. in a horror story, it’s more effective to finish with the girl thinking she’s got away only for the monster to appear right at the end, its jaws drooling, than it is to go into graphic detail about how the monster finished her off, the hours all her friends spent looking for her, how her beloved dog pined for her and so on. There’s no need. Your readers will know exactly what’s going to happen to her and will be able to imagine it for themselves in their minds.