If you are a Heinlein Rules of Writing purist, than you’ll probably run your story through a spell-check, stick it an envelope, and mail it.
However, if you are a little more timid about sharing your stories, I would suggest reading Self-Editing for Fiction Writers: How to Edit Yourself Into Print by Renni Browne and Dave King.
This book has checklists and exercises to help you craft stories that read with a little more polish. I really like this book I’m one of those people who get stuck in endless rewrites. Browne and King’s checklists are fairly objective; they stop me from thinking, “This story isn’t as transcendental as I wish it was,” and gets me counting how many -ly adverbs I have (and deciding which I should keep) and thinking about whether the words I used match the voice of my viewpoint character. Best of all: editing this way can be done very quickly so it doesn’t slow me down from getting my stories in the mail.
Working with Self-Editing for Fiction Writers feels like running a spell-check for your story: “Do I need speaker attribution here?” “Would this piece of information be better shown in a scene or explained in a narrative summary?” “Are my paragraphs thick and dense or are they thin and fast-paced…and is that appropriate for the kind of story I’m telling?” Those are just a few examples of the things you’ll find in this book.
Another helpful part of Self-Editing for Fiction Writers is that it was written by editors, so it gives you an idea of the kinds of things and editor might tell you to change after they’ve bought your story. These suggestions are purely craft-related so you don’t have to worry about it “ruining” your story; it might actually make your story better.