Not that we would presume to tell you!
But you might enjoy p&g's own Bridget Khursheed blog on the subject over at the Scottish Book Trust.
You can find the blog post here. http://www.scottishbooktrust.com/blog/writing/2014/06/where-i-write-old-school-desk.
And if you want to delve further into the Khursheed psyche you can try her on the subject of home http://www.scottishbooktrust.com/reading/stories-of-home/story/the-things-that-remind-me-of-home.