I have this planning technique that allows to view two (or more) paths for a short story. In actuality, I have used it for individual chapters in a novel. Chapters, in a sense, are a complete story within a bigger story. It really does help. It gives enough flexibility for the story, since trees branch off to branches, and it is very easy to use and organize. Most trees don't take more than a page for me; however, my short stories are never truly long. My novel trees are around two pages (or more, depending) long since the chapters are much longer than my short stories.
When I begin, I think of the main idea that will be the conflict of the story. It is the trunk of the tree. After, the plot can spread upward (or downward in some cases when I plan). The smaller conflicts (or actions) are the branches. They aren't specific, but its just a big branch with smaller branches. The example below is from my finished short story Stuck. It had very different paths; however, I chose the one that I thought would fit best within the story itself.
It's a planning technique I started when I was in 7th grade. I suppose it's kind of like brainstorming. Only, I use everything not just some things. I call them trees. It's the story planning that I use when I make short stories (and, occasionally novel chapters).