I'm not saying this is the only way to do it. I'm just saying this is how I do it. So if you find anything helpful here, I welcome you to add it to your routine.
1. Buy Track Pants.
They are just as comfortable as pajama pants, and you can wear them from bed to your desk and back to bed again, and also pretzel yourself in your chair as you work - thus the basis of the appeal of pajama pants in the first place - except that you can also go out in public, without changing your clothes, and you won't look like an antisocial slob. You will, in fact, look like there's a possibility you've just been working out. Or you're in the mafia. Either way, more respectable than old hello kitty pajama pants with cheese dip stains on them.
2. Get a Cat.
Let it get accustomed to sleeping in your lap. Then, when you start to get distracted and think about wandering off to do something besides productive writing (all those random projects and chores that become super high priority when it's hard core procrastination time- I need to deep clean the carpets! We need to fix that sink that's been broken for six months RIGHT NOW. Are those venetian blinds a little dusty? Well, we can't have that! What if the Queen of America stops by for tea? What then??) No need to worry with a warm cat trapping you in place. You'll feel too bad about moving the adorable sleeping kitty, and you'll be stuck sitting there, but hey! you're already at the desk, so might as well write a few words. Genius.
3. Get a Coffee Lad.
This is not an appliance. It's a real guy. One who will refill/reheat your coffee on request. For practicality, I repurposed my husband for this job. He works from home, as do I, and every 90 minutes or so, he'll wander into my office to chitchat about whatever he just read on his fb feed while filling his own coffee mug. So while he's up, he warms up my mug, too. Gotta love him.
4. Build a Garden
You can't get a book written without actual time sitting down in front of your computer (or with your pen and notebooks). But it turns out that sitting down all day, while good for your books, is probably utterly terrible for the rest of you. Exercise has to be included somewhere. Jogging is good, or joining a gym, or finding a yoga studio, but no matter what you pick, most of us will get bored with it eventually. My solution to not enough outdoor acting like a human time is my garden. I have things planted all around my house, and we're adding and changing it a bit every year. It is a lot of manual physical labor to build, weed, water, plant, clip, mow, trim, clean, rake and sweep, but that's the point. It's outside, it requires a lot of different movements and muscles, it's inspiring and meditative at the same time, and I get a beautiful view out the windows for all the work. (sure, other exercise might make me look better, but how often do I get to see myself? And would I want to stare at myself all day, or the beds of flowers outside my office windows? )
5. Do Not Take Yourself Too Seriously, or Not Seriously Enough.
This one's actually about the work. Do not worry that your idea is too serious. Do not fret that it is not serious enough to warrant your time and effort. In short, don't justify why you write what you write. Write what you want to write. What inspires you to buy those track pants, get that pet cat, build that garden and start conditioning your significant other to bring you the coffee carafe like a diner waitress.
And that's about all I have for the moment. You are now fully prepared to write a book. Or at least, no more or less so than anyone else who's set out on this baffling, challenging, winding, weeping beautiful calamity of a road. Good Luck, fellow travelers.