Most of the graphics in Reservoir Dogcows website were drawn on paper first to give them a rough feeling similar to ancient time then scanned to Photoshop for color and detail layers.
Click on each images to see a short animation on how they were layered in Photoshop. Nothing complex, I just want to demonstrate that not everything have to be created from scratch in PS, you can use your art talent to assist you.
GIF Animation (360 kb, 24 frames) of WoodStones.
GIF Animation (92 kb, 18 frames) of Guild Banner.
GIF Animation (96 kb, 18 frames) of Dogcow.