I use Hazel[0] to archive everything in my "downloads" folder after a month. Files get separated into "~/Archive/Images/", "~/Archive/Screenshots/" "~/Archive/Audio" ..." depending on certain criteria (mostly file type). Each sub-folder is broken down by year and month, for example "~/Archive/Images/2015/05/". I also occasionally dump stuff that doesn't belong elsewhere into the same folder system, for example WhatsApp media.
Basically, if it doesn't need to be specifically filed somewhere, I just put it in my "downloads", knowing that it will be somewhat searchable in the archive by either date, file type or in-document search. This is great for all of the bits and pieces that you don't necessarily have a home for or want to manage.