My second novel grew out of an attempt I made at writing a verse novel. I had never written a verse novel before, but I thought it would be interesting and challenging and fun. The book ended up morphing into prose--and fairly quickly--but I found my way into the opening scenes through poetry.
Last year I went to a live performance that included a piece I had written. I'd never seen my work acted by professionals before, and it was a thrill. The whole thing happened because when I saw the call for submissions, instead of saying, "I've never written a performance piece for dual voices before; I can't do that," I told myself, "I want to try that."
Whenever I teach writing workshops, I talk about the great luxury we have as writers--a luxury not shared by, say, brain surgeons--of being able to start over whenever we want. We can delete, copy, produce multiple versions. We can switch a piece from first to third person, try something as a memoir or a novel (as long as we don't call fiction nonfiction), rewrite a poem as prose or vice versa, change the age of the audience we're aiming for, take a stab at a genre or form we've never worked in before. Most of my early publications were short stories. For the better part of a decade I wrote books almost exclusively. Lately I've been writing more essays.
Experimenting is always an option.