I don't know how other people do it, but, this is how I write a good story. I am writing this article (full of trade secrets) because lately, a friend of mine asked me to help her out with writing real life case studies.
The cases happened to her but, after putting them on paper, she still needed someone else to clean them up.
When the lot came to me, this is how I assessed:
1) Too much Information: Too much information, mostly unnecessary or personal which has nothing to do with the story is a definite 'no'. Always remember to take a step back when telling a tale. You cannot become the main character in a story about other main characters. Unless it is your story. If you are a catalyst, then stay that way. Be detached until your cue. Don't clutter your tale with information that is irrelevant.
2) Exposition: Just like good drama, a story should also open with introducing the characters and the problem statement. Don't talk about the nice weather or the cute puppy unless it is for setting the mood. Even then, you should never give it more than 10 - 12 words - max!
3) Character/s: I always create my characters before writing their stories. If your characters are well defined on paper and in your mind, they will tell your story for you. Try it at your own risk though because they will start talking to you and wake you up in the middle of the night and compel you to make changes - joking. But, if you take longer than one sitting to finish your tale, it could become a reality! Don't add unnecessary characters unless they are going to be a part of the narrative with a role to play in pulling the story forward.
4) Problem/s: Your story has to have twists. If your story is a simple narrative of a day in the life of Mr X, it better be more than Mr X waking up and going to the loo and then to work. Ensure that Mr X goes to the loo and meets his match or more in there. Unless there are insurmountable-sounding problems, no one is going to read through it. A story should have enough twists to keep the reader guessing and wanting to know how it will end. Even if your story will have a happy ending or if the outcome is already known from the start, you need to keep throwing twists and suspense to keep the readers glued.
5) Emotions: Don't forget emotions. Humans are a strange species, they have achieved so much in the last few millennia but, despite all the scientific and technical achievements, they only operate out of emotions. Think about it. If your story has the right emotions it will move your audience, make them empathize with your readers and sell your idea. If your tale is cut-and-dried though brilliantly written, don't blame the readers when they stop reading mid-way. You have not been able to build a bond with them.
6) Dialogue: Keep your dialogues simple and short. Write them in the language of the masses if possible. No one speaks using the lexicon to talk to people in real life. Remember, Shakespeare said, "Brevity is the soul of wit." Long dialogues/ monologues and soliloquies are fine for drama but, no one whispers and talks aloud in real life in difficult sentences without being called a cuckoo! Your dialogues should move the story and add drama. Don't waste words on mundane conversations that don't pull the story forward.
7) Resolution and Climax: Resolution is a must. All the open ends in the story should be closed with proper explanation before the end. If even one problem is not closed or one action by a character is not explained the story remains open-ended and loses its punch. All the characters that you have introduced through the tale and their problems should all be put to rest right before you close the tale. There should be NO lose ends.
8) The End: If your story is written for commercial purposes then end it on a happy note. Even if the protagonist has taken a difficult decision, it should make either him or someone else very happy. It should come out as a sacrifice for 'greater good'. This will help by increasing his worth in the eyes of the reader and raising him to the level of a hero. Ensure that at least one character of the story stays with your audience when the tale is over.
Note: Avoid footnotes at the end! Never moralize or summarize. Don't ever make the mistake of putting a note at the end of your story with a moral or a summary. Never! If you want to preach, then do it through the tale and write it in such a way that everyone is able to get the moral without your preaching.
Here's hoping to read good stories!