Composing value structure
I consider the placement of values while working on the composition: this encourages designing shapes that complement the cinematography. Using a tonal arrangement of just a few values, I try simple atmospheric back-lighting that seems to read well enough. The dark foreground diminishes the characters slightly, but helps draw the eye into the distant background.
A chilly feeling
I begin blocking it in, imagining the cold atmospheric wilderness I envisioned sketching the thumbnails. In the back of my mind is The Icebergs, an Arctic painting by Frederick Edwin Church that accentuated deep saturated blue/greens of scattering light through the ice. This is a good opportunity to push some of that effect on the glacier here.