Secret to Writing Success

Two things:
1) Write every day
2) Exercise every day

I suggest a minimum of 1 hour each. If you are not creative enough to carve two hours out of your busy day, then I am sorry to say you are not creative enough to be a writer. If you can manage more than this...go for it.

Another suggestion is to plan one or two longer writing sessions each week, where you can sit down and work for 3-5 hours without interruption. I find these longer sessions are when complex ideas become clear, characters start talking and the big picture of a novel or story will gel. These big-picture things are hard for me to get my head around in a frantic 1-hour session.