A lot of people think the best way to win a short story or poetry competition is to write a really superlative short story or poem. And sure, if you stand any chance of winning any competition, you are going to have to write a story or poem that really shines. I've been both a reader and a judge for several short story competitions (and a winner as well) and I know that not only will you have to write a story that's original and artistic, you'll also have to demonstrate to the judges that you've mastered your craft. You'll have to show them you're a writer who's in control of his/her material.
But even though you'll have to write a really superior story in order to even make the final cut in any short story competition, there are other things you can do to increase your chances of winning and some of them have nothing at all to do with the quality of your writing.
In order to enter any short story or poetry competition, you first have to be aware of the competition. The best way I know of to keep abreast of writing competitions is through the book, The Novel and Short Story Writers Handbook, published by Writers Digest Books (poets can pick up the Poetry Writers Handbook). Sure, the book's a little costly, but any serious writer will get more than his/her money's worth from it.
Timing is Important
Many writers think it's best to enter a competition at the very last minute, right before the competition closes. Besides giving themselves more time to revise and polish their story, some writers think if their story is one of the last entered, and one of the last the judges read, it will give them an advantage. They think the earlier submissions will have been forgotten by the judges or at least eclipsed by their story's brilliance, when in fact, just the opposite could be true.
Eighty to ninety percent of all competition entries are submitted during the week before the contest closes. This is fine if the judges don't begin to read the entries until after the competition closes, however if entries are read as they're submitted, and five to ten thousand entries come flooding in during the final week alone, do you really think the judges are going to be able to give your story the attention it deserves? When judges have to read more than one hundred stories a day, every day, for more than a month or more, they get tired. An earlier, but perhaps inferior submission, might just be "stuck" in their heads and stay there. If your story's a good one, one that's original, well written, and shows you've taken the time to master your craft, it will catch the judges' eye no matter how early you submit.
Quality versus Quantity
Most short story competitions encourage their entrants to submit as many stories as they want. And why not? There's almost always an entry fee to pay, and the more entries, the more money the magazine makes. If you have five really superior stories, examples of your very best work, then by all means, go ahead and submit all five. You'll only be increasing your chances of winning. However, never, never, never sacrifice quality for quantity. The story or stories you submit must be examples of your very best work. They have to stand out, be free of grammar and other errors, and contain that special something that makes the judges say, "Wow!"
Do Your Research
Before you submit a story to any magazine competition, you should first familiarize yourself with the magazine itself. What kind of stories do they publish? What kind of stories do they seem to never publish? Do you think your story will be a good fit? If the stories of past winners are available, and they usually are, read the winning entries carefully. You certainly don't want to copy anything, but you'll get a very good idea of what that particular competition is looking for. If the judges names are available, find out if they're published authors, take a look at their own books, and get an idea of what they (probably) like, what style of writing they prefer, where they're coming from.
Write from the Heart
While your work needs to "fit" in with the publication's view of things, never compromise your own entry just to try to please. We write in order to communicate our own unique vision of the world around us. We write from the heart. We write honestly and we write with passion. At least we should. While our vision needs to fit the competition's vision, never compromise yourself and write something that isn't "you" in an attempt to please the judges. For one thing, it won't work. Most literary judges are very astute. If you write simply to please them, they're going to know it, and they're going to penalize you for it.
Be Fresh and Innovative
Sure, you need to submit literary stories to literary competitons, science fiction to science fiction competitions, and fantasy to fantasy competitions, etc. But within context, don't be afraid to be fresh and innovative. Don't be afraid to be different. I usually write tragedy - either stories that are very poignant or stories that embody high tragedy, but one of my most successful stories is quite comedic. It's still literary. It's still well written, but it caught the eye of a publisher because it was different. In a sea of dead grandmothers, miscarriages, and broken marriages, my lightweight, truly funny story stood out.
Aim for the Top Tier
Competition stories generally break down into three tiers. (Sometimes the judges break down into tears as well.) First, there are the stories that really aren't fit to print. We discard these immediately. Then there are the mediocre. These usually get thrown out as well. Then, there's the top tier of stories, the ones that are all pretty good. This is the tier you're going to have to fall into if you stand any chance of winning a competition. This is where being fresh and innovative can really pay off. Judges read so many stories that are "possible winners," that when one comes along that's fresh and innovative and well, just a bit different, the judges really sit up and take notice. The story might not even be the best written, but it does have the little "something extra."
Try to enter short story and poetry comptetions early, rather than late. Make sure your work is the best it can possibly be, work that's going to make the top tier. Make sure it fits the competition or publication, but don't write just to please the judges. Submit multiple entries if possible and make sure each one is the best example of your work and totally free of errors. Be fresh and innovative, while demonstrating a mastery of your craft. Finally, never compromise your work, your vision. Write from the heart and write with passion and love for the medium.
Good luck! :)