Here is another set of concept sketches for Moths vs Butterflies. Again these are pencil on paper (trusty A5 sketchbook that I keep on hand). These are just scanned and compiled together a little.
I like these last two, they show off the style and the differences between Moth and Butterfly. The basic structure of both is very similar, but culturally the Butterflies are about jewellery, metals and refined construction, the moths love their tattoos, beads and flowing natural materials.