I got this idea from the Terry Pratchett website, via Babayaga's Hut. You have to write a story using exactly 50 words, not including the title. It helps if you write it in word or similar so you can use the 'word count' to keep checking and altering.

The Great Escape, by Jonathan Malory.

Everything in place, the night sky clear; spangled with glittering pinpricks of hope. The full moon lit the way to freedom, their breaths steamed in the springtime air as the grass over the fence waved to them.
Slowly, full of anticipation, the sheep turned to each other and glared silently.