The following elements are important aspects of fiction, but each story will require these elements in differing amounts.  A mystery novel may require very precise and subtle details in order to "prove" the solution without giving it away, whereas an in-depth character sketch may instead require very blunt, unvarnished character details in order to paint a complete picture of an individual.

Are the characters believable?  Ideally, each character should have personal strengths and weaknesses, but even more important are the qualities of desire and need.  The main character should have something at stake, some reason to take part in your story.

What's at stake?  The needs of your characters will drive the story.  In addition, individual characters should have differing wants and needs - the conflict between their goals drives strong fiction.

The order in which the author tells the story.  Whereas the story is a simple chronology of events, plot represents the rearrangement in order to build tension.

The quality a story has when the reader needs to find out what's going to happen next.  Usually, this arises from an unsettled conflict which could turn out either very well or very badly for the main characters.

Is the story light and funny?  Or dark and spooky?  This is a subtle quality of each work, and it results primarily from the diction and setting.

The choice of words within the story.  Ideally, the connotation and denotation of each word should match the overall tone you aim for in your work.

The place and surroundings of the story.  Typically, we need to be able to see where the characters are so we can understand the context of the story.