Thomas had a wonderful post a few days ago in which he basically said, quoting Tolstoi, that happy writers all write in the same way. It's wonderful because it seems so counterintuitive. Aren't there different styles of writing and of writers? Don't some people work better without as much structure?
I agree with him completely. What all happy writers share is
good time and task management: an understanding of the finiteness of time and space
attention to the basics
no excuses for not getting it done
This doesn't mean you shouldn't find the particular schedule, the particular rhythm, that suits you best, or fine-tune the methods that have been proven to work. By all means tailor your time-design individually.
Unhappy writers fuck themselves up in numerous ways, just like Tolstoy's unhappy families. But these multiple ways can be boiled down to a few. I've been an unhappy writer too, so I know what I'm talking about.
Unhappy writers trick themselves into not writing; they are very smart about it too, inventing infinite rationalizations. They view schedules and word counts as uncreative and constrictive, rather than liberating as they really are. On the other hand, they love deadlines! Only a deadline can really get them moving, give them that external pressure. (Remember they have no internal structure to their work so they let other people tell them when they need to get something done.) They don't have a good idea of how much they can get done in an hour or fifteen minutes or a week. As a consequence they are hopelessly busy, confusing activity with accomplishment.
They are too busy to take a break from work, even if, at work, they are endlessly procrastinating. They wouldn't think of writing two hours in the morning and relaxing the rest of the day. They can't do this because they are always behind, never ahead.