There are two approaches to getting your bad self into print. One is to write what's in your heart, what fires you up, what you deeply care about, and then hope someone wants to publish it.
The other--and the two do not cancel each other out--is to choose a likely market, and write something to fit. Most of us who publish on a regular basis take both of these approaches. We may choose one becaus we need to make some money, or because we just love that particular publication; we may choose the other because we are, after all, artists. We have a need to create something that satisfies our inner drive.
Let's talk about that second approach, and see what a few editors have said about what they want, and what they might buy. Their wishes should be clear in the guidelines to their publications, but sometimes those can be oblique, and often guidelines don't give a writer a revealing glimpse into the editor's personal preferences.
For example, one of the lists I follow was recently discussing what a literary magazine will publish. Because that list was one devoted to writers who work mostly in genre, the question was whether a literary publication will ever accept a genre story. Vonnie Winslow Crist, the editor of The Gunpowder Review, a literary magazine devoted to publishing women writers, says this: ". . . if a story or poem is well-written, most editors will bend their “rules” and accept an urban fantasy or slightly supernatural mystery or near-future sf piece. And I think genre flash fiction can sneak into literary magazines easier than a 2,000+ word tale. Unfortunately, things like high fantasy, space westerns, vampire/werewolf tales, military sf, etc. are too genre no matter how well-written or short to fit into most lit mags." This is good to know. A writer can save herself a lot of time, postage, and frustration by knowing in advance what Crist may be open to.
Cat Rambo, writer and editor of the beautiful online publication Fantasy Magazine , says that she wants to see stories of the fantastic that are original. Her guidelines specify "stories of the fantastic that make us think, and tell us what it is to be human while amazing us with your master of language and story elements.” She adds, in a discussion, that she sees too many stories that are derivative, that build on the work and the worlds of other writers instead of being fresh and unique. In other words, don't rewriteTolkien! Create your own world of the fantastic.
Sheila Williams, editor of Asimov's, is very clear that the magazine publishes science fiction. She wants "intelligent, well-written science fiction", and yet still receives stories that are anything but--another waste of the writer's time. The waiting period between submission and acceptance or rejection can be anything from a few days to many months, and in the meantime, the writer is kicking his heels and wondering what happened!
It's not as easy knowing what the glossy magazines want to publish. For some of them, the market is closed to unpublished writers or to speculative submissions (submissions not under contract). That doesn't mean it can't be done. The trick is to really understand what the editors are looking for. Their wishes should be in the guidelines, but a writer must read the publication to know where their real interests lie. This doesn't necessarily mean buying an issue, but if that's what's required, investing five or six dollars in order to study a target magazine is worthwhile.
Glimmer Train is a lovely magazine, for example, with guidelines so open that only reading a few issues will give you a clue to what sort of story appeals to the editors. Their guidelines read "We especially appreciate stories that are both well written and emotionally engaging." Such a tasteful description! But not really very informative, is it?
There are some fine market guides available, and every writer should have at least one on her bookshelf. It's good practice to mix targeted pieces with those come-from-the-heart ones we all so love to write. As with everything in writing, it all depends on your priorities, of course. It helps to know what editors' priorities, are, too!