The other day, I received the most lovely rejection from a UK publication. I mean, don't get me wrong. It wasn't all rainbows and puppies. But it was exceedingly polite.
Don't be discouraged, said the editor, for what may not work for us might be perfect for another publication. Honestly, I couldn't have said it better myself. But sending your story out to another publication is not the tip ('cause you already know that).
Here's the tip: When you see a call out for a short story or an essay or a sestina (hey, it could happen) and it makes you think of something you wrote, months, even years ago, pull out the piece. Chances are good that you'll see something (or a few somethings) that make you sorta, kinda squirm. In other words, welcome to that big old room of improvement. Take a seat and get to work. Maybe there's a better way to move your plot, a more interesting way to express your theme, or maybe your sestina was more like a rondeau (um, I don't pen sestinas or rondeaus. But that's not the point here, people). Bet you'll see all kinds of ways to make improvements.
And even if you know it's a long shot, sending your piece to a British publication, at least now, you're motivated and you have a much better piece than you did before. And then, if you get a lovely rejection, send out the piece somewhere else. Because there is a pot of gold at the end of one of those rainbows. Might as well be yours.