This is a story checklist of everything to keep in mind.
Start
Get some Writing Software.
A Premise
You'll have to have an idea for a story.
Groundwork
Some writers like to outline their story and characters. To do this, you'll want some Mind Mapping Software.
If there's any research to be done. Do it.
You should have an interesting character or two in mind, so now you might want to start looking at the Three-Act Structure to outline your plot.
Plotting
When thinking "What could happen next?", remember that your characters should be driving the plot. The plot shouldn't be funneling your characters down an avenue they don't fit or decide upon—the less coincidental events, the better. If the reader is to respect your protagonist, they must be active, not passive, by having goals.
When coming up with scenes, remember to enter late/exit early, show, don't tell, and add conflict that blocks the scene goal.
Work suspense and subtext into your scenes if applicable.
Plant things early on that will return later.
Try to avoid coincidence. Again, see active protagonists.
The audience need time to relax every so often, so don't forget to give your character breathing space to reflect.
Establish subplots.
While Writing
Decide on the best point of view, voice and tense to tell your story with.
Start with a good first line.
Beginnings.
When writing dialogue, try to have subtext. Show, don't tell.
Be self-critical, but not self-doubting. Reading a few paragraphs from a bad book that sold well can inspire.
Rewriting
Check your work for split infinitives, comma splices, dangling participles, consistency of tense, pleonasm, paragraph focus, incorrect apostrophes, commas, colons and semicolons.