Find Example Artwork
As stated in our article about multiple character design methods, finding example artwork is incredibly useful for picturing the character you want to make. While this art should be replaced by character release, nothing can help you visualize a scene more than knowing what a character looks like in the first place.
An easy mistake is to not save the image and its source. You never know when you need to contact an artist you like to work with you, or to look at their art gallery for more inspiration. Even worse if you lose the image entirely in an editing mistake.