I read about the Graham Greene Challenge on Fuel Your Writing. It’s a 500 word challenge, but not just writing 500 words as a short story and then stepping away, done. Graham Greene’s challenge was to only write, exactly, 500 words of the manuscript/ book he was working on and then walk away to leave it until the next day. That means stopping at whatever word comes up as #500, no matter where it is – even if you don’t finish your sentence.
Torture? Perhaps, clever torture though.
Try it. You’ll need something to let you know when you’ve come to #500 and then when it dings you have to stop. Won’t you be itching to finish it? Won’t you be just raring to go when you can start the next 500 words? I bet all kinds of ideas will be flowing and you won’t be able to get the whole thing out of your mind.