Once upon a time I worked in a bakery...for about three days. It was kind of fun, kind of funny. One task taught to me by a kind but verbally challenged worker was the process of what she called "emerging" the doughnuts. It involved a screen that pressed them under the hot oil, and they did eventually "emerge" from it completely cooked.
I do my best writing when immersed in the story, but sometimes it takes a lot to get there: a lot of time, a lot of silence, a lot of freeing my mind of other things. It's a little like meditation in that it takes practice and persistence to reach the state I need to be in. It can't be forced, and it's extremely fragile. Every ring of the phone, slam of the door, and demand of the cats is a block to Nirvana.
I know people who write in bits and starts (like Jon, with his 70-hour-a-week teaching job), and I wonder how they find "the zone" with limited time and tons of distractions. I applaud their efforts, but I need to be immersed before my best work emerges.