I had one of those 'Misc' folders in my photo files. I had carefully saved photos from several different computers, from zip files, from camera cards, and CDs into this one folder. I finally took the time to go through it one photo at a time and sort them out properly. I had more duplicate files than I'd realized. Better that than to know I have a photo and not be able to find it. Many of my early digital photos are very small. While I deleted a lot of duplicates, I only deleted about 1 GB of data.
Since I changed the organization of my photos, I'm going to hook up my second EHD and make sure that my local data backup is up to date. My Backblaze backup will automatically update itself. With my non FIOS connection (can you hear me whining?) it won't be quick, but it is automatic.
I use a date and description system for sorting my pictures. Before 2005, they are sorted by subject and sometimes also by date. Pictures after 2005 are sorted by year, with a separate folder for each event during that year. For example, inside the '2008 Photos' folder, there is a '2-14-08 Valentines' sub-folder. I store the pictures with the alphanumeric name the camera assigns. I'll append to the alphanumeric if I edit the photo, so I won't confuse the original DSC6442.jpg with DSC6442adjusted.jpg. I'll re-name the photo to 'Roses for Valentines 2008.jpg' only if I share it.