Art preprod for large projects?

Snowfly

Broad topic, I know, and maybe a bit hush-hush for some...but I'm curious as to what types of art preproduction practices you have in place at the studios you work at, and what types of assets and documents come out of it by the time production starts.

Please bite :-) Cheers!

SouL

Mood paintings and maybe some early reference and studies of the main story characters.
Nothing very defined, obviously. Just general art pieces that give everyone a sense of direction. Anything from original artwork to reference photos of particular areas.