I'm very likely going to start the painting on this one over, but I figured I might as well post what I did.
I got part of the way though and realized that I should really be working from front to back with this one.
Meaning that the mouth closeups should take priority, and then I'll be able to figure out what exactly I want to do to compliment them as I get to Shuten and then to Ibuki, rather than just doing random things with Ibuki without a concrete plan for how the whole painting will come together.