Here's where I have got to so far.
I stuck on the diecut letters and shapes and covered with texture paste which I stamped into as well.
I primed with Grey paint, washed that over with Clay, then another wash with Black.
I then Rainbow painted my letters and shapes.
I might crackle paint my letters and shapes for a glossy look.
Perhaps rub some metallic pastes into the backing?
Just not sure where to go now?