I typically go through about a dozen story ideas before I get excited enough about one to actually write it. Most of them die a quick death inside my head when I realize there isn't enough meat on them to keep me excited enough to go through the hours of work to write a 200-400k story.
Occasionally I start trying to write one and after three pages or so it becomes apparent it's not going anywhere. I save it and usually never go back.
Of course, there have been a couple of times I went back. My story Gender Bender, about a Lois and Clark who were each born as people of the opposite sex didn't have enough for me to write a long story. So I went back a year later and wrote a vignette.
Occasionally, some of the ideas can find their ways in as part of other stories.
But that's the way it is for me.
