I started travelling on trains a lot when I was invited to run children's events based on my books. I soon realised that public transport was a wonderful source of free life models! I try not to attract attention, keeping my sketchbook hidden below a train table or behind my handbag, so my victims remain natural. I often show them the results though, and get into all sorts of interesting conversations with complete strangers. The coloured sketches are generally tinted when I get home, although on rare occasions I take a tiny travelling watercolour set out with me.