My original CC folder was unorganised and I created it in 2016, which was around the time I started playing Sims 4 with CC for the first time. There are lots of broken CC files and everything is in the one folder. I don't use the savefile that uses that CC folder anymore, which is a legacy family and I still have save in my game now. I re-named it old cc folder on my laptop and it still has 2752 items, which comes to 10.7 GB. I haven't added to the folder since last year and I haven't put it back into my game since then either. I will delete it at some point.
Currently, I have a new CC folder that I made in October 2017. This has organised sub-folders for each category of CC. Make-up has seperate sub-folders for each piece (eyeshadow, mascara, blush, lipstick and facepaint....well contact lenses instead.) Sub-folders have made my cc folder, much more visually pleasing to look at. Also, I haven't been so willy-nilly to install every CC I see on TSR, like I used to in my old folder. I only download the items I want. My new folder has 2092 items and is 9.55 GB (not far from my old CC folder haha~) I use more mods, than I used to...so I need to remember to update them after certain updates and patches. I am also starting to realise there is some CC I am not using at all/anymore, so when I get the motivation...I will use the tray importer tool to find and delete the unwanted CC.
I made a Maxis Match CC folder seperately, so I have a savefile for just MM sims and it is also organised with sub-folders for each CC category :)