Call them Keywords, Tags, Categories, whatever you like. Just use them for cataloging your images. Keywords are probably the most important bits of Metadata available to you.

Create your own personal Keyword list

Look through your old photos. Thinks about the types of pictures you take. Think about how you would go about describing and finding photos you’ve taken. Start writing.

Think about Keyword Groups. Lightroom uses this principle. I have a group called Flowers and it includes keywords like rose, tulip, orchid, etc. Make one for family members. Another for Birds or Trees. Whatever suits your needs.

Short and sweet

Keep your keywords to no more than a 2 word phrase. Christmas party Ed’s house 2007 is a Caption. Break it down to party, Christmas, ed’s house. Don’t worry about the year since it’s in the EXIF data or the filename if you include it there.

Being able to search by the word Christmas means you’ll get all the photos from previous years. If you’re looking for that "great shot of the snowman we built a few years ago" you’ll find it.

Print your Keyword list and put it next to your computer if that helps. You don’t want to misspell anything, although some software pops up a list of currently used keyword as you type. (Thanks Lightroom for making my life easier)