I started writing novels while an undergraduate student, in an attempt to make sense of the city of Edinburgh, using a detective as my protagonist. Each book hopefully adds another piece to the jigsaw that is modern Scotland, asking questions about the nation's politics, economy, psyche and history ... and perhaps pointing towards its possible future.

I still think most writers are just kids who refuse to grow up. We're still playing imaginary games, with our imaginary friends.

I think writers have to be proactive: they've got to use new technology and social media. Yes, it's hard to get noticed by traditional publishers, but there's a great deal of opportunity out there if you've got the right story.

A lot of writers, especially crime writers, have an image that we think we're trying to keep up with. You've got to be seen as dark and slightly dangerous. But I'm not like that and I've realised that I don't need to put that on. People will buy the books whether they see a photo of you dressed in black or not.

I'm often asked how I write books, but I don't think my approach is suitable for everyone. If I walked into a creative writing class, all I could say to them was 'I tend to make it up as I go along.' I'm not sure that's brilliant advice.

I love short stories - reading and writing them. The best short stories distill all the potency of a novel into a small but heady draught. They are perfect reading material for the bus or train or for a lunchtime break. Everything extraneous has been strained off by the author. The best short stories pack the heft of any novel, yet resonate like poetry.

It was the laughter of birthdays, of money found in an old pocket.