I am not a huge tag user. I find the search very good and the Linked/Unlinked mentions tab enlightening.
However, I do have a few categories of notes I want called out. So I will drop a hashtag at the bottom of the file, below a Horizontal Rule, where it is out of the way. I’ve found I like this better than using YAML front matter.
As I type this, I realize that all of the tags I care about are types of notes and thus have templates associated with them. So each template includes the tag. I barely even think about them except when searching.