When you have a long project, like a dissertation or scholarly book, you are writing, it is best to have writing rituals that will keep you on track. Most writers who are successful in their work write daily and schedule the time into their day to make sure they can focus on the task ahead.
It is best to write at a time that works in your schedule. Don’t tell yourself you’ll get up and write and 4 AM if you are not an early riser, as you most likely will not get up to write. Instead, schedule a time to write when you can close a door and have some quiet (when your family is asleep; when the kids are at school; between a regularly scheduled meeting when you have a block of time, etc.). Put your writing time on your calendar, and treat your writing time as you would an important commitment.
Remove distractions: the laundry will wait; Facebook will still be there; email does not need to be responded to immediately. Put your phone on silence so a call or text won’t disturb you. If necessary, disable your Internet connection so you can’t go online to shop or surf the ‘net.
Give yourself a realistic goal. Setting up a realistic goal will allow you to be successful. You cannot write your dissertation in a day (or a week or a month). Instead, approach your writing by telling yourself that you will write on a specific section of a chapter for this long each day (2 hours; every morning; after dinner, etc). Doing so allows you to meet your goals and finish the project at hand.