Here are a few different styles of example I use to communicate the Art Direction to the team members.
This was for Scarface 2.
Quick sketch with supporting references and the proposed color swatch for the location.
This is a more complex game mechanic example, with multiple interior sketchs and a 3d geo proposal of the interior layout and references. 
These next 3 exteriors, are Art Direction design and supporting reference for colors, I use Maya to help for the construction and communicate the vision quickly.



The following is a paint over done in Photoshop over a screen capture of the game to help in tightning up the look along the way.
