How fast do you write? That's a related question. Some authors put out one book a year, Some put out 5 or 6. Some people write 100 words a day, and some write 5000. We're all individuals, and we all write at different paces.
But how on earth do we find time and motivation to finish our stories? In this regard, I've changed over the years. I have come to realize that I can write THE PERFECT story, obsessing over every word and revising for months, or I can effectively write a very good story that I am happy with and get it out into the publishing world.
Because here's the thing: production does matter. Unless you are a Dan Brown or a J.K. Rowling, and a single book will garner you a million sales instantly, having your name in the public eye with new releases every few weeks or months is the key to building a readership and sales.
This isn't easy, but it is doable. This is what works for me:
1. While I'm working on a project, I write every day. I may not be in the mood, I may not have hours of time available, but I write something every day. A single scene. A revision of an earlier scene. A piece of dialogue. If I can, a whole chapter.
2. I don't edit as I go. I just write. I just want to get words on the page. I don't agonize over the perfect metaphor or dialogue tag; that I can do later, when I'm editing.
3. I give myself deadlines. I'm a Type A person, so these work well for me. I usually take a look at one month, or maybe a couple of months, and block out on a calendar what needs to be finished/revised/booked/sent to an editor and when. This calendar sits right next to my computer at home.
4. I stay off the Internet while I'm writing. I don't open Facebook or Twitter or Google or MSN or anything else. I just write. Social media sites are a HUGE distraction.
5. I don't get caught up in spending time on promotion. Yes, it's important to interact with readers online, and book ads, and study your sales trends. You know what's more important? Releasing a new book.
I work full time out of the house. I don't have kids, but I do have a husband and family and friends I spend time with on a regular basis. I go to the gym a few times a week. Last year I published 5 books (of varying lengths) and I'm on track to do the same this year. I never thought I could produce books at this rate, but I haven't felt too overwhelmed yet.
Have faith in yourself. Set a manageable schedule for your writing, and be kind if you fall short. But as one writing colleague told me not long ago, if we only wrote 1000 words a day, and took off 2 months for vacations/holidays/weekends/sickness, we could still produce around 300,000 words a year. That's 3 full-length novels, or 5 short novels, or 15 novellas.