When it comes to writing, I’ve heard from many writers that the biggest thing you need for productivity and longevity as a writer is the ability to write consistently. You don’t write only when you’re inspired. Even when you don’t feel like it, you sit down and put your fingers on the keyboard (or typewriter or longhand, if you’re so inclined). It doesn’t matter how you get those words down. Just get them down.
I recently wrote about setting word count goals. I’m not sure I’ll make my 50,000 words a month goal, but that’s okay. I’m writing consistently and productively. I’ve hit at least 1,000 words 10 of the last 11 days. Over that time, I’ve written over 18,000 words. Per day, it doesn’t seem like a lot of words, but those words add up. At this write, I should manage three books in a year without too much of a problem. Of course, there’s also the revision process, which I need to get better about.