In the past few months, I've changed my writing schedule. Instead of trying to write 45 minutes a day, I've been trying to write for two hours three or four times a week (and 45 minutes on the off days).
Until the holiday season I was doing this fairly consistently, and I noticed something. It's the second hour in which all the breakthroughs are made. All the twitching and losing concentration is done in the first hour, the sitting staring at a problem poem, then putting it away and staring at a blank page--that's all first hour stuff. In the second hour, I finally stop resisting, stop looking at the clock, stop noticing all the noises around me, and the ideas come to me. Two or three or four big problems that I've been struggling with in a poem or two are suddenly solved in the second hour when, as if by magic, the right words or forms or ideas come to me.
Really this should be no surprise to me; I've written before about how the subconscious mind does all the heavy lifting. It takes time for the subconscious mind to solve the problems (which happens before the sitting down, which happens in the days and nights and weeks in which I've been pondering problems), but it also takes a quiet conscious mind to receive them, and for me, that takes more than an hour to achieve. But when I get to that quiet settled-in state, there they are, the answers. And now I know that getting to the receptive state comes (for me) in the second hour, not the first. Good to know.