So when asked how I do it, my response is always the same. I schedule time, like I would for a doctors appointment or a kids activity, and guard it. It's my time and, outside of emergencies, I don't give it up. I find the golden time for writing in my house is between 9 and 11 pm. My kiddos are in bed, the dishes have been done and the house is quite. I'll usually throw a load of laundry in and fire up the old lap top.I also use wasted time to my best advantage. I've been known to write while my son's at Tae Kwon Do. I eat lunch at my lap top. I have even been know to write at the kitchen counter while trying to cook (not recommended...it leads to crappy writing and burnt food).
Another great thing I've done is join a writers group. Mine is online, but I have a small group of people who are following my work. I feel obligated to produce something for them to read. So I move forward. Ira Glass from This American Life had the best advice. "Put yourself on a deadline so that every week you will finish one story." So my main motivation is one chapter a week at the very least.
So do I write 3,000 words in a setting. NO. I'm averaging about 900. But I'm moving forward. Until the publishing fairy drops off a big check and I can hire someone to do my job...I'm still punching the 9 to 5 clock.