Have you ever noticed how incredibly useful Tintin is when you need an idea for something? There's so much information crammed into every book. I often used to turn to it if I needed to find a design for a face, a posture or a colour scheme... then I stopped when I realised how many other people were doing it too!
Here's a page of faces from an old sketchbook:
Obelix makes a cameo at the bottom ^-^