Take some words and write something!
Something involving this probably exists somewhere within this site, but I thought I'd throw it out there anyway. Besides, it's not fair to keep my favorite writing prompt to myself.
First, grab a word source; I suggest asking any nearby company for two to four random words, but randomly flipping through a book or the dictionary and finding a word works fine as well. Now write something weaving those couple of words together. Let it go in any direction it wants, even if it picks up a tale in the middle of its telling, doesn't have much of a story line, or seems downright weird. The fun of it is seeing where it goes.
Maybe you could leave your inspiration words at the bottom of the story, or in a comment, just so long as we know what you were working with.
If you're looking for any inspiration, some of my favorite have been "dystopian barber shop"; "poodle haircuts", "a duck named Albert", and "cheese"; and "bear", "deer", "wetsuit", and "window".