In addition to a number of annual contests, Writer’s Digest hosts a monthly short-short fiction challenge. They provide a prompt, often just an opening sentence. Interested writers submit a story of 750 words or less. The WD judges select five finalists, and the winner is chosen by votes of registered members of the Writer’s Digest forum. You need to register for the forum, but once you do, you can read the current finalists as well as the stories of past winners, which is an education in itself. There is no money involved but winnning entries are posted in the print magazine and on writersdigest.com
http://writersdigest.com/YourStory/
I had the notion that I could never write this kind of story until last fall, when I really needed a mini-vacation from my major project. It was mid-October so my thoughts turned to ghosts, and over the next few months I wrote several very short stories. Now I find them rewarding, like quick sketches, like a way to test ideas or try out another genre. A chance to visit Mars, or Paris, or Hoboken.
Save the link. One day it may be just the change or breath of fresh air you’ve been wanting.
The First Gates 
I have trouble doing a grocery list in under a thousand words, so it would be a real challenge for me. But what is life if not a challenge. Maybe someday…
LikeLike
It is certainly an acquired taste. On several occasions, a compelling image or premise arrived almost fully formed while daydreaming or walking (or both). It can then be very satisfying to get a complete beginning, middle, and end on paper pretty quickly. Then I would put it aside and come back at intervals, or sit down and finish it in a week or two. A bit like quick like in a sketchbook.
LikeLike