Figuring out what tag, folder, collection, label, insert-categorization-system-here, to use is just so hard and irritating.
I rarely use hashtags, and I can barely get myself to use Google+ Collections, and my Evernote content is a mess all because of this.
Interestingly, Google really helps you out in this area with Google Photos which just magically does all the categorization for you.
Weird.
Evermore tries to help, too, if you tag stuff.