Time
Would you really be any more productive without children around? Yes, writing time is necessarily stolen time, but it was when I worked full time as well. The first draft of the first book was written piecemeal - I used to get up an hour earlier in the morning and write with my keyboard balanced on a chest of drawers, steal lunch hours in Chelsea library or St Luke's garden, and scribble my way home down the King's Road on the top deck of the number 22. I remember working on the manuscript in a high rise looking over Kuwait, and in a hotel near the auction house Drouot in Paris when I travelled on business. It was finished off in a whitewashed villa in the orange groves of Valencia. 'Love & Loss' has literally travelled the world with me.
Its latest travels have been less exciting - to the coffee shop while my son is at nursery (should have shares in Cafe Nero), and between bed and basement as it has been edited and rewritten. BC (before children), I would write first thing and many people find this the best time, when you are rested but deliciously still half asleep. If you are just starting out, do try Julia Cameron's method of writing free-form morning pages ('The Artist's Way' and 'The Vein of Gold' can't be recommended enough).
Now I work late into the night while they sleep through necessity, as most mornings we are up before 6am with the children - earlier if the pilot has to be at the airport. Sleep has become a luxury, something I long for. In 'Becoming a Writer', the excellent Dorothea Brande advocated the usefulness of writing while in an artistic coma. She wrote this book about the writer's magic in 1934, but it is honestly one of the best - (who else would bluntly tell you to give up on writing if you can't do the exercises because you would be better off doing something else?) It may feel like everything else is a juggling act - like you could do better at being a good wife/mother/daughter/friend/housekeeper/writer, but with small children, sleep deprivation and a book waiting to be written, working in the grip of an artistic coma is something that comes effortlessly.