How do people use Tags in Finder?
I can't say that I love the tagging system, so I have very limited use of them: but I've used tags in two ways:

1. For final version documents
Since I often have several versions of the same file on storage, I have one tag named "final". So it facilitates spotlight searches like "quote client tag:final". This is the only use I've been able to stick to constantly, since I often find myself searching for the final version of a document.

2. For document types
Since I use my folder hierarchy to separate different projects, I use tags for document content types. For instance, named tags "Proposal", "Specs", "Guide", etc. This offered the small benefit of allowing shorter file names (intended to avoid names like Proposal_CustomerName_ProjectName.ext. I wasn't able to stick to this tagging style, since longer names seemed still seemed efficient, even if they're not pretty.

I rarely browse files in finder, mostly I search through spotlight. So the only real benefit I see in tags is being able to type "tag:abcdf" in spotlight. With this approach, since everyone organizes in a different way, I guess the key question is: 

Is there a criteria that you often find yourself wishing you could use in searches, and which doesn't really fit in your file naming styles or folder hierarchy?