Is This Mars? lives or dies on its pinks. So before we modeled a single dune, we painted three look-frames — dawn, noon, dusk — and got Daymoon to sign them. Those three images became the constitution every later decision had to obey.
Grade first, model second
Locking color early flips the usual argument. Instead of "does this dune look good?" the question becomes "does this dune look like noon?" — which has an answer. Modeling went faster because taste was already decided.
The palm rule
The hero palm is eleven hand-placed fronds instanced into a crown: close enough to touch in the hero frame, cheap enough to render everywhere else. Nobody has ever asked how many fronds it has. They ask how it feels — which was the whole point of the look-frames.
Decide the feeling first. The geometry will follow.