One of the most important things for writers to do is challenge themselves.
It's also one of the hardest things to do.
I know what I write; I have an idea what I excel at. I like stories with adventure and excitement; maybe a little bit of suspense. The good guy usually wins, although not in the most obvious way. Somewhere along the journey, there will be something so absurd, I'll have to laugh (and hope the reader will chuckle, too). I employ, for better or worse, a lot of pop culture references. At least one character in the story will like sports or make a sports reference (often, this will involve referring to the New England Patriots as "evil"). A character or characters will have a background in the Midwest...that's where I'm from, that's what I know.
Of course, these guidelines are not absolute. I have several stories that have none of these characteristics. It's hard to work an Indianapolis Colts reference into a story set in another galaxy, even if it's entirely possible that Peyton Manning was sent from beyond to save pro football in Indianapolis.
So, I play with these conventions and themes. I embrace them as part of my style. Writing reflects who you are and you shouldn't be afraid to inject some of that into your stories. You just have to be careful not to fall into self-parody or predictability...something I admit I fall prey to from time to time. Usually, I catch it. Usually.
I started this post off by commenting that writers need to challenge themselves. This means trying out different styles, settings, and characters. I've had limited success in the superhero genre, but I can't write those types of stories forever. I can't turn every story into a cape-and-cowl affair.
I've tried some different types of stories and narrative devices, but one I can't seem to nail is horror. It comes down to enjoyment and familiarity with the genre. When I think of horror stories, I think of tragic ghosts and vampires and serial hook-murderers and grim stories about death and killing. That's not a fair assessment of the genre, I know. I just don't enjoy reading those types of stories or watching those types of movies. I'm not the type who picks up a book or watches a movie to have his spine-tingled.
Since I have a limited background in the genre, everything seems to come out too formulaic when I attempt to write it. A "great twist" ends up being something horror readers have seen a dozen times before.
The truth is, I have no real desire to write in that genre, but if the right anthology or the right idea comes to mind, I'd consider dabbling in it. I just think I'd have to read a lot more horror stories to really "get" that particular style.
And that's really the point I'm making here. In order to write, you have to read. Otherwise, you'll just end up rehashing familiar story ideas and themes without even realizing it. And no one will want to publish your work.