I am chock-bursting with good story ideas. Give me a prompt and I can hack out an awesome original outline in a week or less. Just ask my wife, who endures my many crazy story ideas with good humor and patience.
I'm always limited by my ability to actually produce the stories, though.
For process, I get a story idea as a flash of inspiration usually. Frequently it is sparked in reaction to some new weird idea I read, a story I almost liked, or any of the many weird things that happen in my immediate vicinity. These inspirations usually go something like, "What if X happened, but with Y character and in Z setting?" Or "How would people respond to X event?" or "what if [weird religious claim] was literally true?" something like that. Not all of these are good, some are only good for a laugh. The best ones are usually dealing with a personal issue that I don't have a satisfying answer to. An example might be:
"What if a Paladin was in a world where every organization was thoroughly corrupted, how could he carry on?"
Then I create a character who can contend with the idea in an interesting way and a world that can reflect the idea in a way that will pose challenges to them. Then I go back and refine, revise, readjust both protagonist and setting until they match each other just right. I create antagonists and secondary characters who can act as interesting foils for the lead, challenging them and taking the lead out of their comfort zone. At that point, I've probably thought of a dozen or so interesting scenes for them to be in, and then it's just a matter of putting the scenes into a sensible order and connecting them up.
Then I'm ready to write a first draft outline. After that, there's a lot of refining that happens as I grope towards the story's true self. My self-editing process is relentless. At long last, I have an actually decent outline and a strong idea of every element that needs to appear, and it's mostly a matter of writing it down straight ahead - that's usually storyboarding for me. Finally, my editor makes suggestions and tells me if something isn't working right, and we do another draft or two.
After that it's just production.