How much attention do you pay to the effectiveness of your writing habits?
Some writing habits work at certain times or places, but not at others. And some habits have a lifespan: they're effective for a while, but then they just stop working.
An example: I wrote the first year's worth of content here at Quick Writing Tips using a surprisingly easy process. In a seven-week period, with a time commitment of just two hours per day, I completed more than 100 posts. This period, one of the most productive writing periods of my life, happened during a mini-sabbatical my wife and I took in Hawaii.
When we returned to our home in New Jersey, however, this seemingly "easy process" failed miserably. I tried all sorts of tweaks and variations to recapture the magic, but nothing worked. The most frustrating thing was I didn't know why it failed. I never did figure it out.
That's when you ditch a process and try something new. Don't try to force something to work when it just won't.
Be vigilant and mindful of your writing habits. Are they effective or not? If so, apply them consistently and with discipline. Exploit your effective habits for all they're worth, and ruthlessly eliminate those that are ineffective.