My writing process begins when I first get an idea. Generally, I come across ideas in three ways. I see an idea in popular culture or a website and think about modifying it in some way, I receive an idea as a suggestion from another (which can be a commission), or I come up with the idea organically.
After I have the idea, I usually spend several days playing around with the idea in my head. On rare occasion, I sit down for hours with a notepad planning it, though usually I just let the idea bounce around in my mind when I have a free moment.
Once the idea has developed, I progress from conceptualizing the plot to writing out key scenes in my mind, which is also usually done in an undisciplined manner. Finally, when I feel comfortable with the idea, I type it. By the time I type, I want most of the creative work to be over, so I can focus my mind exclusively on tasks like creating quality sentence structure.
If possible, I like to type a story all at once, or at least to create individual chapters all at once and treat them in my mind as if they are stand alone stories. This is difficult if I don't feel I've creatively fleshed out what I want to do beforehand. I've found writing a bit here and there without a predetermined plan tends to make for a poor, unfocused story, so I'll wait until the last minute if needed before starting the typing phase.
After I've finished typing, I try to get a fresh pair of eyes to check it for typos when possible, and wait a bit to see if I want to make any tweaks. Generally, though, I try to limit my tweaks to things like avoiding using the same word over and over. Trying to second guess content can lead to lengthy and complex revisions, especially with short stories, which often don't even improve things and can even make things worse.
Here's a common example of how a post-typing content edit can sabotage writing. Let's just say you want to describe a character as getting more and more angry over time. You have two good examples of character's buildup, and then an explosion. Upon re-reading, you feel the need to add a third example. This one doesn't quite fit into the plot, so you have to add in some 'explanation' to make it gel with the rest of your plot.
The result? The story either bores the reader or leaves them confused. They start to wonder why the scene was added, and the focus and momentum from the two good scenes is squandered, which in turn limits the effectiveness of the climax.
If you are a fellow writer, let me know how your creative process differs from mine in the comments section. I look forward to hearing from you.