To prevent muddying your mind, your environment should consist of only four things:
- Reference Material
Anything else present, is present, in your mind. Extraneous stuff will poke and prod your mind — in short, it will distract you.
So, take a hard look at everything around you, and if it isn't a supply, or for reference, or decoration or equipment, then it needs to be removed from your working environment in order to remove the mud from your mind.