Eliminate distractions ruthlessly in your mind and reading.
As many of you may have found, writing is complicated by distractions and, often, by your deleterious mood.
If you are having a hard time writing, stop reading for a while. The words will start to foment in your brain; they might spill over in unexpected ways.
Stop writing flash and short stories; only allow yourself to write words for your novel.
In other news, here is a centaur I am drawing for my new backburner series.