Do you ever base your characters on real people you know or have worked with in the past?
Not not really. When Flaubert was asked who inspired the character of Madame Bovary, he replied 'c'est moi' - it's me. That's hoe it works for me too. All my characters start life representing some aspect of my own personality and life experiences. Then they develop a life of their own and can surprise (and occasionally shock) me!