For me, sitting still and trying to reach a daily quota or write a single chapter without stopping is difficult. So I typically map out what I want each chapter to cover ahead of time. On most occasions, I type about four pages at a time and then I walk away and do something else. I repeat that process continuously throughout the day. When the day is done I've usually typed about twenty pages or a chapter of my work. That has been my process for combating writer's block!