If you're like me and save a lot of stuff to Evernote, you may forget to tag notes from time to time. You may also have rules set up in Gmail to auto-forward emails with specific keywords to your Evernote email address (something I do for any emails containing the word "receipt"). In the latter case, as far as I know, Evernote will not automatically add tags or place them in the appropriate notebook for you.
Every once in a great while, I like to go back through all of these untagged notes and tag them. I'm just OCD that way. If you'd like to do the same, instead of scrolling through your list looking for anything with blank space under the 'Tags' heading, type this into the search bar:
The asterisk (*) acts as a wildcard, and forces Evernote to display every single note that hasn't been tagged yet. You could also use an actual tag in place of the asterisk if you want, like so:
I don't really do this myself, because it's only useful in instances where you're looking for every note outside of the search term, and I can't think of a time I've ever needed to do that. Anyway, in case you were wondering, I used quotes in the second example because that tag is comprised of two words, and without the quotes to specify the exact tag, Evernote won't know what you're talking about.
While we're talking about search, you can also type something without the minus symbol (-) to find all things contained within that tag, i.e.:
If you have a ton of tags like I do, this will save you the trouble of scrolling through your entire tags list and clicking the correct one.
Evernote's search tool is pretty powerful, and an essential tool for power users and I'll probably write more about its functions in the future.