I assembled the elk, primed them, and painted them dark brown. They were highlighted with medium brown, and then with lighter brown. You do not need a good pointy brush for that, and I used a fairly large hardware-store brush, myself.
I painted the antlers dark gray, and highlighted the edges with light gray. The harness was painted with reddish brown to contrast with the elk brown, and the tail was painted off-white for contrast. The nose was painted black. I used a large brush for all of that, but the nose was painted with a pointy brush.
I glued the chariot wheels to the chariot before priming, and the pictures show my process of painting chariots step-by-step.
It's a good idea to use contrasting colors - what colors, is up to you. I chose a "Biblical" look for these chariots.