Hi there.
On my hard drive I have 1 folder called Audio for all the hard drive recordings I do, I also have folders named TVN (my 128 voice edits and WAV sounds), Styles (this folder has 11 sub folders for the T2 style catagories eg. POP, ROCK etc) CUSTOM VOICES (this is also split into sub folders for piano/strings/guitar etc) then I have a folder for registrations and 1 for multipads so everything is quite organised. It takes a while to set it all up but good housekeeping helps.