The best advice I can give on this is, once it's done, to put it away until you can read it with new eyes. Finish the short story, print it out, then put it in a drawer and write other things. When you're ready, pick it up and read it, as if you've never read it before. If there are things you aren't satisfied with as a reader, go in and fix them as a writer: that's revision.
Neil GaimanThere are lots of artists in the world. But there's only one you. And the only person who has your point of view is you. If you decide not to make things, all you've done is deprive the world of all the stuff that only you could have brought to it.
Neil GaimanThe boy had the towering arrogance only seen in the greatest of artists and all nine-year-old boys.
Neil GaimanOften the adult book is not for you, not yet, or will only be for you when you're ready. But sometimes you will read it anyway, and you will take from it whatever you can. Then, perhaps, you will come back to it when you're older, and you will find the book has changed because you have changed as well, and the book is wiser, or more foolish, because you are wiser or more foolish than you were as a child.
Neil Gaiman