There's no such thing as a stupid mistake...unless you keep doing it!
Anyway, 2015 has been a great year for me so far as I established myself as a freelancer again and this was an essential experience for me. My plan is to invest a portion of my earnings into an educational fund and do something like this every year.
Initial digital thumbs-
Final value study-
Final digital colour pass plus image references -
First part of tonal underpainting-
Colour glaze being applied over sepia values -
Final painting (dried!). It survived the flight home and is now framed in my front room :)