So professional texture artists have there own texture library which are filled with a large variety of their own created textures and photographs, there would be multiply folders for different environments. Here is a website which contains the examples of how texture library are layered out. This is a great reference for me to work from.
Link to Website – http://www.mayang.com/textures/
Reference – mayang. (N/A). Mayang’s Free Textures. Available: http://www.mayang.com/textures/. Last accessed 09/03/2015.