Plan it or let it flow?

Yesterday I set aside the whole day for writing. I exercised early, cleaned the kitchen, put the laundry on, made a cup of coffee and sat down to work by 9:00am. I've been making slow progress with my WIP so I was determined to complete chapter 10 and 11 by the end of the day.

There I was, fingers poised over the keyboard, collecting my thoughts. I knew what my character was going to do, what would occur as a result, and I was eager to make it all happen. After five minutes of typing, I was...