Tags are a fun, quick way to use a few materials (tidbits and scraps, even) to whip out a little accent piece to be used now or later. They can be designed around a specific theme to help tell the story. Or, they can be stockpiled to later be incorporated into larger spread as an accent to tie it all together and add detail.
Tags are versatile little punches of color, texture, and detail. They are fun to work on when I have no particular direction in mind. Just quick little ditties when my fingers want to cut and paste, but my mind wants to wander. I have a box of them that I enjoy browsing through. They can even be the inspiration themselves!