First of all, please don't judge my shopping problem! (Yes, I had that problem before I became a CT) But, here you go. (Windows user)
My process:
Buy the kit. Open my Downloads folder. Unzip it there. Combine the pieces into one folder - all papers, elements, alphas, word art, etc into one folder. Fix name as needed (delete pp or ep, add BYOC/DD if needed). Then move it to the Designer Folder.
I have a folder on my hard drive called _Scrap Stuff. _ because it shows up first!
Then inside that is Store Folders.
Inside my TLP folder:
TLP Collab is exactly that: Any Store Collab. Individual Collabs are stored in the Designer Folder.
TLP Month Kits: Memory Pockets Monthly, Create Crate, Mixed Media. The Add-ons by designers go in their folder, but the main kit goes here.
Retired Designers get an xRET in front of their name so they go to the bottom. I can still use their stuff, but it helps me remember it's not current for challenges.
Inside Pink Reptile's Folder. I combine all the kit pieces into one folder. If there's multiple alphas, I will leave 1 folder with the alpha inside the kit folder. But only one alpha? I'll drag the whole thing in one folder. Also, you can see Bakers Gonna Bake was BYOC so I added that to the end of the folder. Falala was Document December 2017, so I added that to the end. That way, I can just open my Lilypad folder and search BYOC 0717 and all the folders that match that will show up for me. I started this in 2017, so some of my older kits don't have this designation yet. I'm slowly getting those all added as I use the kit again.
The last trick I use is to add an underscore _ to the beginning of the previews. Okay, 2 tricks. I also make sure the preview says "preview". Because I can search preview in Windows and they will show up for me. Sure, it takes awhile if I search the whole TLP folder! But I can, or I can search a designers folder for a specific designer challenge. And see the kits I have from them.