So, lately I've been messing around more with production specifics; most significantly, the debate over which type of sounds are best presented in mono, which are in need of stereo, and why. When recording a rock piece (or music that requires more traditional instrumentation), you have a basic idea of what should and shouldn't be mono, it's basically cut and dry. The kind of thing I do, though, isn't really something you can consult your amateur mixing-for-dummies resources to get advice on.
With more experimental music, however, there's really no indicator of what should be stereo or mono, except for heavy bass, which generally (always) should be mono. How do folks here determine what to put in stereo or what to make mono in compositions? What sort of sounds and sound ranges/types fall into one category or the other?