I use tags. A lot. Think of it as a “folksonomy” (ok, contrived term but here: https://en.wikipedia.org/wiki/Folksonomy )
I use the Ultimate Tag Warrior plugin. For each post I make, I give it some descriptive tags. These tags show up at the end of the post and are used in a variety of ways.
1) Offers some keywords for the regular search engines (minor)
2) Offers keywords and searchability for the blog search sites such as Technorati.
3) By clicking on a tag, my blog will show you other posts that had the same tag. An easy way to find related content.
4) For those who like such things, it is also an easy way to build a tag cloud showing what sorts of things have been blogged about and (by size/color) which of those come up more often than others.
(note, you can click over to my blog to see some of this in action. However, right now the “click on a tag to see more” is a bit broke due to another plugin that I’m trying to resolve…)