After my Mods folder hit 30 GB and the game loading time was longer than 30 minutes, I started using multiple Mods folders.
When I use each folder, I rename it Mods. I have a text file in each folder to keep track of which is which. (BTW, I work as a bookkeeper and tax preparer and payroll specialist for a small business.)
In alphabetical order, I have "Mods build-buy testing" (varies based on which build-buy objects I am testing), "Mods career testing" (currently 26 MB - all career mods only) , "Mods CAS full" (contains all tested CAS content acquired to date but nothing else: 22 GB), "Mods CAS testing" (varies based on which CAS cc I am testing since I move content into and out of that folder between plays and generally dress most/all the Sims in the town each time I play that save), "Mods CAS testing 2" (only a few Sims in this save use custom content, varies in size depending which CAS I am testing), "Mods crash testing" (if my game won't load after I put cc into a folder, this save is used for narrowing down the culprit), "Mods food testing" (contains all my edible and nonedible food cc/mods): currently 519 MB , "Mods full" (39 GB) - contains almost everything that has been tested except new TSR sets, "Mods Harry Potter" (I hate replacing existing lots, but this save I used a 64x64 Hogwarts lot to replace the park in Willow Creek - just couldn't resist): 113 MB, "Mods no CC"(268 bytes includes the .cfg file and the text file), "Mods pose testing" (contains tested CAS, poseplayer mod and poses):2.02 GB , "Mods scripts testing" (nothing but script mods, and none are ever removed unless there is a patch that breaks this save): 5 MB , "Mods test 1"(for testing multiple types of content and a mod or two: 2.25 GB, "Mods tested good 2" (contains all tested custom content since I split my Mods folder up except TSR sets, but no script mods): 29 GB, "Mods test 4" (varies depending on content being tested), "Mods test 6 and 7" (varies based on content being tested), "Mods test 8" (varies based on content being tested), "Mods traits testing" (all traits tested since Seasons patch came out plus new traits being tested): 196 MB , "Mods TSR sets": (TSR sets in testing and tested TSR sets that are downloaded as numbered zip files) 17.8 GB , and "Mods Unsorted" (varies based on content that I haven't sorted into any category yet...usually a download that is ambiguous in its name about its creator or content type. I recently moved a swimsuit named "2" out of the Unsorted Mods folder into Mods tested good 2 under Mods/CAS by type/Swimwear.
Thank you for reading this mini-book.