Adding depth and atmosphere come into play using volumetric. Haze, light blooms, fog, all this is added within volumetrics.
AOVs are the render passes that will be produced for the final image composite. The passes each contain different portions of the images that when brought into photoshop help bring the image to life.
Setting up your render settings and saving them will become critical to be able to repeat your processes and get the same results each time.
Inside of Photoshop with your render passes you start building your final image using the AOVs.
