I have a heirarchy that works for me and reduces confusion. I typically do not have a scenario like yours of so many iterations of a file, but my build would be to setup a main job folder consisting of a job number inside of my accounts folder. So, it might look like this: Accounts > Client's main folder > folder w/job number. Inside the Job Number folder their may be another sub-main folder of the particular job: Brochure 082009 and then another set of sub-folders for each particular file: Brochure 082009 > Illustrator Files > Photoshop Files > InDesign Files > Word Files, etc., etc. Inside the Photoshop Files I setup another set of sub-folders: Photoshop Files > Original Files > loRes Files > hiRes Files > GIF Files > TIF Files > EPS Files > JPG Files.
You wouldn't have to setup all of the sub-folders unless you had specific GIF, JPG, or TIF files, etc. Although I do not recommend it, you could use the same file name in each separate and appropriate file if you wanted to. I do not. Instead, I name each file and make sure I have it appended properly. For instance, you download a file AOK1234.jpg, I'd put it in the "Original Files" folder and save a copy as Broch_Cover.tif and put it in the "Tif Files" folder, etc., etc. If, for some reason, you wanted to use the same pic for a web page comp, I'd save the appropriate version as Broch_Cover.jpg in the "JPG Files" folder for later use and resave under a separate web page folder. You could go a step further and add CMYK or RGB to the file name: Brochure_CoverCMYK.tif or Brochure_CoverRGB.tif so that you would know which one is the original and which one is the conversion file.
I like my approach because it allows me the ease of linking images and knowing exactly where to find a particular file. It may seem like alot of work setting it up, but saves me tons of time in the long run. Keeps things organized and less confusing. Plus, it helps archiving for publication when sending a disk to a printer or outside vendor. You already have the client's job folder and all of the support files in one place, so you could literally copy the entire job folder to CD or DVD or a .zip archive for upload.
Here’s a common situation:3. Then, you create a layered PSD in CMYK.
Just addressing this one note specifically:
If you are placing these CMYK images in InDesign, you may consider leaving them RGB which will save you time and a little disk space. Sometimes layered CMYK is warranted to ensure black type and elements output as 100K, but if you don't have this concern, InDesign color management can convert the RGB images to CMYK on output.
It's a good workflow, as long as you use Proof Setup and Proof Preview to see the destination CMYK soft proof.
If I download a Jpeg from a stock image agency it stays untouched as the original.
I then save it as an RGB PSD. that now becomes my working file. Everything stays as RGB until I make my PDF in ID.