So that's why I'm writing this at 6am while I'm walking to work.
Literally walking. I glance up every four words or so to check there isn't a lamppost or dog turd or pedestrian (rare at this time of day, in the route I take at least). Just dodged a jogger there.
I write on my phone (an iPhone, although the technique is certainly possible on any of the modern smartphone platforms) using an app called PlainText which is free with ads on the AppStore or £1.49 (I think) without. I happily paid the £1.49 after a few weeks of use because it's a great app.
The beauty of PlainText (and there are other apps that do this) is that it syncs with Dropbox, the wonderful free cloud storage service. What this means is that I can happily tap out a new chapter on my phone when I'm on my way to work or waiting for the kettle to boil or queuing in the supermarket and the text is automatically stored in the ether. When I get home in the evening and get the laptop out for a prolonged burst of writing all the work I've done on my phone is there waiting for me in my Dropbox folder. The syncing hasn't failed me once.
What I end up with is a series of separate .txt files, one for each chapter, which at the end of the writing process I can copy and paste into a Word document for uploading to Smashwords and Amazon.
Beyond that I have only one rule. Don't go back until the end. I write a chapter, review it once and then move on to the next one. The fact that each chapter is a separate file makes it much easier to resist the temptation to go back and tinker.
So that's how I wrote a 90,000 word novel in 6 weeks whilst also having a full time job and raising a young family.
And in case anyone is wondering, yes, a few paragraphs of Sunliner were written in the smallest room of the house.