The "I-Have-A-Cool-Idea-But-Nothing-Else" Story
Successful short stories, especially science fiction and fantasy, are built on cool ideas. It's that wonderful What if? of Inspiration that sends a writer to the computer faster than anything else. We just can't wait to get it down on paper.
There's nothing more deflating as an editor than being excited while reading a story with a super cool idea, only to find out that there's no story to go with it. And, you might be surprised at how often we encounter this. The situation is not well-developed, maybe the characters are flat, there's no plot, or the worst: there's no ending. It just peters out. The whole thing's gone all lukewarm on the page and it feels like a true missed opportunity.
Here's a cool idea: scientists have invented a way for people to be in more than one place at a time. If I write only about characters who do this cool thing, that's not a story. I have to write about what happens when those characters do that cool thing. Where's the struggle? The conflict? The resolution? Who does or doesn't want them to? How does it change them? What are the unintended consequences?
Before writing, think it through. Think: this is my inspiration and enough of an idea to hook the reader, but what kind of characters and action can most effectively carry this cool idea so that it evolves into a full, satisfying narrative.
You don't have to outline unless you want to, but it helps to have some idea about the ending. Where does this go? What am I going to give the reader that makes this worth their time? If you can't imagine what the pay-off is going to be for your reader, then maybe it's not quite ready yet.
There are some exceptions, but usually we keep reading because we care about the characters, not the cool ideas. But having both is golden. If you can thoroughly meld your characters and their actions to that idea, then you'll have a winner.
Remember: a cool idea is the starting point for a story, not the story itself.