Character study

I've just been listening to an interview with Irvine Welsh on Radcliffe and Maconie on 6 Music. He had a lot of interesting things to say, but I was particularly struck by a technique he uses for developing a new character. He imagines the sort of music that person would listen to and then immerses himself in it until the character emerges. Isn't that a good idea?

My son (the one with the Creative Writing degree, not the drummer) says he draws a picture of the elements he knows - landscape, clothes, scenery, weapon, whatever - and the unknowns gradually become the knowns. Other writers I know start by think about the sort of shoes a person would wear or what their bedroom would look like. As I consider this now, I realise I always have the accent in my head.

If you're a writer, what's your top tip for bring a fantasy cast to life?