From Mumbai Boss:
“I have two different routines depending on whether I’m writing a book or not. I write a book once every four-five years, and it normally takes the best part of a year to put the thing down on paper: the shortest was nine months for Nine Lives, the longest From the Holy Mountain which took 18 months.
Writing up one of these history books is like a final year of a four-year course in university. The first year is easiest and lightest, I’m going on book tours—to Paris or Rome or Milan or America—doing lectures and readings on the previous book, and while I’m doing that I finalise what the next book is about. It’s the least-hard working year, I’m popping into libraries, sending emails to other historians in the same fields. Year two is more secondary reading, so I’m reading all the stuff that has been put in previous books about what I’m writing about. Year three is about archives, sitting in Delhi National Archives or Lahore archive, or in Kabul, as I did for Return of a King.
During that time, I’m usually stuck in a library with nose in a laptop. I have a very highly tuned filing system which I’ve got down to an art. All the material has to be properly prepared and perfected. I liken book writing to Chinese cooking—the real effort is chopping up ingredients, all gingers in one pile, beets all marinated, so at the very end when all the things are ready to go, I put pan on heat and start the cooking. And if you’re well prepared the cooking should go easily, and you should have it ready in nine months to a year.
More here.