The more prolific I've been getting, the more settled I am getting into a particular process of writing that works for me.
Summarize like a madman. Here are the characters and this is the plot - what happens in the story. I'll tinker with the mechanics and milieu to make it as interesting as possible. This is the stage where I'll often decide the style and intent of the story. I keep working on this until I come up with an interesting potential ending.
The next draft is to develop the characters, by asking what kind of character would get him or herself into a position like this and why. All the stories I'm writing these days are about relationships. Sometimes parents and children, sometimes siblings, sometimes lovers and sometimes more than one of the above. Creating realistic relationships with a few lines of dialogue is just about the most fun in fiction writing. The quirkier the characters, the more fun this part of the process is. Very often, relationships will change during this stage. Sons turn into daughters, parents turn to children, friends become partners.
This is where I try to find and pull out the beating heart of the story - the pivotal moments from these lives that I'm trying to capture. The characters very often won't be aware that these moments are pivotal, but the writer needs to find them and display them to the reader in the most entertaining and emotionally affecting way possible. The ending should be an epiphany of some sort - to either the reader of the character or both.
Edit down to the elements that are essential to caring about the characters telling the story. Add some bells and whistles, make sure the voice is consistent and compelling...and then polish.
At least - that's my idealized process. It sometimes goes off the tracks or stalls at one of the stages while I work shit out. These elements have been common to about six of my last seven stories.
If it helps anybody else write their stories, then it's worth sharing. Meanwhile I'll be watching and trying to learn from my favourite writers.