Gmail encourages users to "search not sort". I do that. Email works great for search. For files though, sorting is often better.
I have well over 20GB of files synced onto my Dropbox. The rest of my computer is spotless(I use Windows 7 and do a fresh install every 30-60 days). But the Dropbox can get cluttered. I take a simple approach that is a hybrid of search and sort. Here's how to do it:
Put files into 2 sections:
Here's what the end result may look like:
-My Dropbox
--Music
--Photos
--Blog
--eBooks
--Company Docs
--Search
The first directories are the ones you access a lot and are well sorted and maintained. The last directory is a mess of random files and folders that you've collected. You can browse through it, but it's easier to just run a search on it when you need something.
This a hybrid of search and sort.