My EHD's mirror my D: drive on my computer:
Main Folders:
Canon Downloads
Digital Layouts
DSKMU (digital scrap kits most used)
Images 1
Images 2
Images 3
Images 4
Canon folder is where all photos are downloaded. When I got my 1st Canon camera, I set it to download to folders with the naming convention of YYYY_MM_DD. I still do that. I try to have no more than 2 years in this folder. They then get moved to the Images 3 folder. I set up a folder for each year, with a sub-folder for each month (i.e. 201401Jan, 201402Feb etc). Then the daily folders get moved to the month folder.
Images 2 has all of my scanned photos within folder names by year/event.
Images 1 and 4 are miscellaneous photos.
As for the layouts folder. I have 3 sub-folders: 600x600, Layouts, and PSP Layout Files. Each of these sub-folders is set up with the same sub-folders. I am a theme scrapper so all my folders are by theme, i.e. 2024 DYD, 2024 Oct Daily, Book of Me, Dogs, Family etc. The Family folder has sub-folders as well. When I scrap, I keep the pspimage (layered file) in that folder. The 3600x3600 jpg file in the Layouts folder and 600x600 jpg files in the folder for them.
I have moved some of the theme folders off of the D: Drive and they are on 2 separate EHD's. Basically those are older themes that I no longer have anything to scrap.
I do have a Vacations folder which has layouts for all of my vacations where I had photos to scan. The layouts for a cruise I took in 2010 are in their own folder tucked away safely on the EHD's since it is all scrapped and printed. Since I have taken 4 vacations the last 2 years, I now have a specific sub-folder in the Vacations folder for them. i.e. 2024 Cape Cod, 2025 Canada, and 2025 South Dakota (forgot 2025 Vermont!) I also have a sub-folder for Disney in the Vacations folder that has all layouts from my 5 trips to DW and DL.
This all makes sense for me since like I said, I scrap by theme. If organizing by theme works for you, go ahead and do it!