I've paraphrased four of Kumar's rules (numbers 2 and 4-6)
1) set a modest daily word quota
Many a writer has recommended setting a word or time quota for each day's work, but what caught me about Kumar's rule is the modesty: 150 words? Easy.
And I think that's the point. "On better days, this goal is just a start," he says. "Often, I end up writing more." And I have too, since I've started. Some days. Others, I manage the 150, maybe 160, and then it's time to get back to my day job or I just run out of steam after a long day. But when you meet your quota--granted, a quota with the sufficient authority of a professional author behind it--you feel good.
Kumar writes: "Each day is a struggle, and the outcome is always uncertain, but I feel as if I have reversed destiny when I have sat down and written my quota for the day. Once that work is done, it seems okay to assume that I will spend my life writing."
The 150-word quota seems to click with not only the time and energy constraints of being a writer "on the side," but also the insecurity that goes along with it.
2) isolate yourself from yourself
Of course, turning off access to the Internet (which, by the way, if you're using a laptop, should be as easy as switching off the adapter) is one of the more direct ways on average to do that.
But there are other things. Music. Windows. Light. Furniture. Pain. Worries. Anxieties. Future.
These must get switched off, silenced somehow, someway, for productivity's sake. The trick, maybe, is to be selective. Some of the contradictory pressures that comprise your self ought to be channeled into the act of writing.
This is all very obtuse, but at least turn the Internet off. This, I think, will get most of us 80% of the way to where we need to be to write effectively in a session.
3) take short walks
I've found that a short walk by oneself can stimulate the mind and allow thoughts to take their natural course. Writer's block can manifest as dammed up thoughts, ideas that you're afraid to let fall. Let yourself daydream them out while you stroll.
4) identify books with which you are "in conversation"
Kumar writes: "Choose one book, or five, but no more than ten, to guide you, not with research necessarily, but with the critical matter of method or style. Another way to think about this is to ask yourself who are the writers, or scholars, or artists that you are in conversation with."
While of course our goal as writers is that vague, doubtful theoretical ideal, "originality," I can see the benefit of acknowledging and being honest (and perhaps humble?) about the authors, thinkers and works with which one stays in conversation philosophically and aesthetically. As Bradbury and King both admit, one's early writing is going to be parodic to some degree because we're learning by example. But even as you diverge, you're still probably comparing yourself to specific writers and works.
If nothing else, this rule seems like a reflective exercise that I feel could be quite useful.