I have a little less than 2 gb after cleaning out a gig worth of cc and mods. I am very proud of myself and yes, I am a cc addict. :D
I think I must scroll through my mods folder daily, I have 1600 files and I swear I know them all. I have had some cc for ages, I get very attached to certain outfits, hair and furnishing/building items. If I don't use cc in a certain amount of time, I will delete it. I don't separate mods/cc into sub folders as I have had my share of stuff not showing up in my game for one reason or another. As long as I keep it under control, I can identify every piece of cc...if I can't id it, it goes.