One of the things that helps my writing the most is writing consistently. My best writing is usually done in the evening. For some reason, my ideas flow and I'm able to get a lot more done if I'm not utterly exhausted. But with my kids growing up, a set schedule is something that I can only dream about happening. Even my evenings aren't what they used to be as my kids stay up later, but still need to be tucked in at night.
By consistency, I mean taking the time to write each day on a regular basis. When I am consistent, I am able to accomplish more when I do sit down. It's like exercising. If I am running three miles a day, then it is easier to get up and run, no matter when I do it. While if I haven't exercised in awhile, the idea of running three miles is daunting, and my body fights me every step of the way.
For me consistency or writing every day is the key to being successful at writing. I'm not always perfect at this, but I am trying. What about you?