If you really want to immerse yourself in the environments where your scenes take place, you need to check out Tabletop Audio (http://tabletopaudio.com/). Tabletop Audio is a fantastic resource of original, 10-minute environmental and contextual ambiances. Currently there are 91 different ambiances to choose from, such as Dark City, Lively Cafe, Sleeping Dragon, Winter Woods, Industrial Shipyard, Dungeon, Victorian London, 1920s Speakeasy, Abandoned Fair, and the list goes on. The content is all created by one very busy guy and he’s updating the content regularly. The ambiances, which some are accompanied by minimal music, break up into categories like fantasy, sci-fi, historical, modern, nature, horror, etc.
The practical use for writers here is simple: You’ve got a detective whose climbed down into the sewers to search for clues on a human trafficking ring? Pop on over to Tabletop Audio and click on the Sewers track. Immerse yourself in the environment through your headphones.