Do you just write the story that tracks through your brain or do you write with a specific market in mind? For me writing for a market is plain torture and it shows in the writing, so I tend to write the stories as they come to me, then search for a market. Not the best way to work, I guess, but most days that works for me.
My response, which I thought I'd share here:
But here's a tip you can take to the bank (literally):
Select a publication you'd like to write for. Study it. Study the guidelines to determine what they say they want. Study the stories to determine what they actually publish. Then force yourself to write stories for that publication. Submit those stories. Pretty soon you'll discover that inspiration provides you with market-specific story ideas.