Red Sonja

cave woman with pelt and a club in the woods........

Nothing specific, but as you mentioned arty and retro in your likes, start on those themes?

Make it funky and abstract too perhaps!

While I don't have an idea, I do think it's less important than the execution, and on that basis I have no doubt you will do something very pleasing, whatever theme you pick.

good luck with it when you shoot!