When I wrote my first novel, I wrote only when the "muse" came upon me. Sometimes I would write for hours, sometimes I went for weeks without any significant accomplishment. When I finally completed the novel, I felt drained and couldn't even look at my computer.
I took a few weeks to do research on another project before I approached the second novel in the series. This time, I vowed, I would not make the same mistakes. I set a goal for myself, to write everyday, even if it was only one sentence, one paragraph, or one scene. And, by doing so, I found I had a rhythm to my writing.
I divide my writing into two sessions, one during the day, and the other at night. During the day, I seem to struggle with what I want to say. My mind wanders, I can be easily distracted, so I write what I can, to reread and edit in my second session.
My evening sessions seem to be a joy to me when it comes to writing. There are less distractions, my mind seems more focused, and the words flow. I have been averaging 1200 words a day since I started dividing my sessions and keeping track of word count. And, I write more at night. Since I have always been a night owl, that did not surprise me. What did surprise me was that the time seems to fly by. I get so involved in the story, I have to pull myself away, or I will never sleep.
I never thought of myself as a person who would follow a writing schedule, but the more I do it, the more productive I have become. It has also helped me to prioritze what needs to been done in my other writings, such as my blog, articles, and research. So, if you find your writing suffering, don't chalk it up to writer's block. Try a schedule for a few weeks. You may be surprised with the results.