I don't suppose this is a very controversial idea to most people reading here, but translating it from idea to action can be a bit of work. We tend to write what we want to read, and to a degree, what we're comfortable with. Risk doesn't mean being transgressive — there are entire subgenres dedicated to transgressive fiction, with critical and commercial apparatus around them. I should know, I sometimes swim in that pond. Risk in this context means doing things we're not comfortable with, specifically embracing the possibility of failure.
When I first went on my story-a-week program, back in the day, I explicitly gave myself permission to fail half the time. 50% of the stories would be fit only for the kill folder. 25% would be fit for extensive rework. 25% would come close to the mark. Those were my earliest goals.
I gave myself permission to be wrong half the time. Dead, unsellable, creatively bankrupt wrong. I failed in this goal, as even early on the number of "kill" stories wasn't much over 25%. In recent years it's dropped very close to 0%. But it was important to me to allow myself to risk looking stupid in my own mind, in the view of the Wordos and my first readers, in the view of acquiring editors.
Rejection can be considered another form of failure. (See here and here for discussion of my philosophy on this.) I wrote about 100 first drafts before I ever sold a story. Collected about 200 rejections doing it. This over an 11 year period, counting from 1990 when I first got serious to 2001 when I first sold. Lifetime to date, I've written about 440 first drafts and sold about 230 stories, collecting about 1,100 rejections along the way.
Sure, my ratio's gotten a lot better, but I put my ass in the wind a long time before those numbers flipped over my way.
I still take risks. Some of my most beloved stories have not sold — "Dream of the Arrow", a straight up literary novelette about my experiences in prep school (seriously); "Love in the Time of Metal and Flesh", a very dark experimentally-structured novella about extreme body modification, murder and innocence. Did I fail with them? No, because they both meant a great deal to me when I wrote them, and I learned from them.
I can't recall the last time I retired a story still-born. It's been at least a couple of years. That's the reward of all that risk, the fact that these days almost all my literary children get a chance to make it in the world, whether or not they actually manage to fly. I still get rejected three times out of every four submissions, but eventually I sell.
Back in 1990 I believed I'd eventually sell. Years of risk taking, and psychotic persistence, have shortened the timespan involved in that eventuality. I'm still taking risks, and looking for more, because trolling the edge of that waterfall is how I improve.
If I ever stop taking risks in my work, lay me down, because I'm done.