I’m a big fan of Phillip Reed and have backed over a dozen of his Kickstarter projects. (He currently has 76!) He writes a lot of system-less supplements for RPG gamemasters. They’re primarily about adding ‘flair’ to a campaign and are fun to read.
His recent project, Dungeon Illumination, made me think about Fancy lighting for texture and effect. I missed the window to pledge but I’ll pick it up when it comes to DriveThuRPG. How a dungeon is illuminated sounds trivial but I put an enormous amount of effort into getting the lighting right because it really enhanced the aesthetic of the game. For the moment I’ve only implemented torches. At some point perhaps I’ll get inspired to add other types of light sources with different colors and properties.