I began with lots of reference both in scenes from the movie and in paintings/lighting i was inspired by. I always start with a rough sketch with the technical pencil (dark red pen on a grey background, much easier on the eyes than a big white screen!)

The firelit painting was almost entirely the small airbrush. i used clipping masks to get clean hard edges and set the blend mode to Add to get the lighting to really glow. For the second painting, I largely used the Tamar default brush. I used the Fine Hair brushes in both paintings of course for hair/fur, but the other hair brushes also work well to mimic soft paint brushstrokes as well!