There are many possible ways to keep digital scrapping files sorted. I start by using the file system in my operating system, which is Windows XP. I've got a folder under 'My Documents' that I named 'Digiscrapping.' Inside that, I have it broken down by company. Under each company, I keep kits separate. Kits are divided into folders for paper, borders, ribbons, charms, tags and so on.
But I don't actually use Windows XP to find files when I'm working. I use Bridge. Bridge is included in Photoshop, but not Photoshop Elements. In Bridge, every file is tagged, or given descriptive words that apply to the file. Bridge won't do this automatically, you have to do a lot of pointing and clicking. The first tag I put on a file is the name of the designer. Then I add tags for paper, label, charm, border, color or whatever. Some files have many tags, some only have one or two. Because of the way Bridge can be used to sort by tag, I can go into multiple folders at once and get all of my ribbons. I can even tell it what color ribbons I want.
What I've found is that most computer users have some system of sorting and organizing files that works for them. Of the many systems that I've seen, the ones that work the best have clear and specific labels and they are internally consistent. If a complete stranger had to go through your computer to find a particular file, and they could do it without resorting to a general search, your file system is organized enough.