I have written fiction for twenty-five years: published three novels and a collection of short and novella-length stories, as well as have a desk-full of novels and short stories in progress. Below I have summarized the questions aspiring authors ask me and my answers to them. Hope this helps you write better stories.
Plot:
All well written stories follow the simple, 3-act structure: Greek Tragedies to Shakespeare to Spielberg.
Act 1:
Beginning
Introduce the setting and time (solidly ground your reader so he knows where and when)
Introduce at least some of the characters (so your reader can begin emotional involvement with them.)
The precipitating incident (why start the story now?) Also use this to hint what the story is about.
Begin action NOW! If you haven't done something interesting (the hook) by the third page (of a novel-length story) you've probably lost your reader. Shorter stories, even sooner.
Act 2: Middle
Build the story
Two steps forward, one step back. Difficulty makes forward progress sweeter.
Your readers want to see small victories and failures on your character's path to the big victory.
Build from small to more significant and important happenings. Build tension via failure.
Act 3:
End
Your story's climax
Summary & wrap-up (if Romance, then end with Happily Ever After)
Memory Dump
Don't dump a lot of description in all at once, especially right at the beginning.
Sprinkle it in as your story proceeds.
White space (makes your story easier on the eye and brain):
Vary sentence length and paragraph length. Keep sentence length to 24 words or less.
Use dialogue to give the reader's brain a change of pace
Use thoughts (internal dialogue) to give the reader's mind a rest from action
If you can't read it out loud a week later without stumbling, fix your stumbling block.
Let the characters 'live and experience' what you want your reader to experience. Through your characters, let your readers live it, too. Don't just tell them! (The old adage: show, don't tell!)
Character Development
Characters should grow, change, and develop as a result of what they do in your story. Else, why have the story at all?
All major characters, even your villains, must be someone the reader can become emotionally involved with (either good or bad). Enjoyment of reading comes from emotional attachment and involvement. Without this, the story will be flat, and if the reader does finish reading it, he/she will end up frustrated and dissatisfied. You don't want frustrated readers.
Character Goals, Motivation, and Conflict
(GMC). Each character must have all three.
Goals:
What does the character want? (It's best if goals are both surface and deep-rooted)