So, now that you have your sacred writing space taken care of, the next thing you need to do is write.
This is my favorite mug... (on the other side it has 'Romance writers make novel lovers').
The washing will wait, so will the tidying, and the cleaning, and the cooking. I put writing first. I have to put writing first or it will disappear entirely, and the damn book will never be finished. Then I'm left feeling irritated, frustrated, overwhelmed and cranky. I am a much nicer person when writing comes first, trust me.
I'm not saying that anyone needs to spend four, five, ten hours a day writing whilst their beautiful children turn into tv zombies and quietly (or not so quietly) starve to death. But I give myself some time every day to write, and then get on with the chores. That is being a writer. Ten minutes of writing on a hellish, out of control day, is going to still makes me feel like I'm getting somewhere. Not opening my manuscript, but having all the laundry neatly folded, does not move me closer to my goal.
Being engaged with your writing is also something that'll keep you moving forward. So, if I'm early to pick up the kids, I spend that ten minutes focussing on my plot, plot problems and holes, having ideas, considering character. I jot down notes, often on the back of old receipts which I then lose and spend fruitless time searching for only to find them three months later on the floor of the car.
Its not just using down time either - when you are busy doing things that don't really engage your brain, get into the habit of thinking about your work. I believe it was Agatha Christie who said she got her best ideas when she was doing the washing up.
This all might sound a touch obsessive, but seriously, to push through and get an 100,000 word manuscript written needs a touch of obsession. I have calculated that to get 100,000 publishable words, I write in excess of 300,000 words (that also has a lot to do with my writing style, and other writers don't work that way). When you have a busy life (and who doesn't) and conflicting priorities, you need to be very focused on what you want, and how you are going to get it.
You want to be a writer, then you write.