As of now, I have about a dozen short stories in various stages of being written. A couple of them are just started, most are toward the middle of the tale in question.
Short stories need to have a good tale, well told, with just enough detail to allow the reader to see what you see. But given that you are asked for 3000 to 8000 words, if you want to submit it for publication, you have to keep verbosity to a minimum.
So, I tend to go off on a tangent, then start a new story rather than finish and fix the one I'm working on. This is a bad habit.
At least with novels, I do have a better habit of attempting to finish one before starting the next. Of the various novels I am working on, only one still doesn't have any sort of end. The others, generally need more work on both the first chapters and the final one, but they do reach some reasonable end point.