The next time you're at your desk thinking you should work on such-and-such piece, ask yourself, Does my next breath come with a genre? Does it come packaged with the label of Short Story or Screenplay or Sonnet?
Writers should practice not knowing which genre they're about to write.
Not knowing genre joins other important forms of not-knowing for mindful writing: not knowing the point of re-entry in a draft (but knowing already which piece one wants to work on); not knowing which piece one will work on (but knowing the genre of that piece); and not knowing if one will actually produce any words at all during a writing session. These types of not-knowing are needed to engage verbal emptiness--the space/time in which formless turns over to form and vice versa. At the most basic level, these forms of not-knowing are also necessary to remaining perceptive of the present while writing.
Notice that I say practice not predicting genre. Don't get me wrong: maintaining a focus is important. We need to narrow our intrapersonal to finish pieces. With a mindful writing practice, however, we allow ourselves numerous opportunities for the opposite of narrowing: a radical openness to the moment.
What we're trying to do is maximize possibility and reduce preconceptions, especially what Ellen Langer called premature cognitive commitments. In Mindfulness, Langer writes about how "mindlessness, as it diminishes our self-image, narrows our choices, and weds us to single-minded attitudes, has a lot to do with this wasted potential."
To increase our creative variables and contexts, it's preferable that we approach each present writing moment with mental windshield wipers that clear away all. Then we listen for whatever intrapersonal bits and phrases arise in that moment. By setting up a mind clear of assumptions, we are likely to hear a greater range of the intrapersonal in that call and response between our writing selves and the next moment. To remain longer in that state of openness, we try to not label this new intrapersonal material by genre (on top of trying of course not to evaluate or critique it).
Without present awareness, genre is a major form of preconception and nonproductive mindlessness.
Picking genre too early forecloses on possibility by exponentially and very quickly reducing structural and content options. Preconceptions freight the writing moment with faulty assumptions and limiting self-talk. Second only to the preconceptions about our writing ability that most of us tell ourselves while writing is our preconception about our genre.
During invention, there's no real need for 100% commitment then & there to the contexts & people affiliated with certain genre. Those people are not physically present while you write. Those contexts are not your context while you write. Our #1 allegiance during invention should be to observing the ever-changing present moment.
This is especially true of professional writers and students in school for creative writing. Graduate writing programs usually ask graduate students to declare their genre and sometimes undergraduate programs do as well. Genre for writers is a like a pearl: grit of past experience (a writing class taken in college, a passing compliment, a book read as a teenager) accumulated layers and layers of actions to make us "a poet" or "a novelist," and so forth. Actually, a series of moments accumulated and hardened into what now seems timeless, just how it is, the personal status quo.