As you begin to shoot more images, it becomes harder to seek out and find that killer shot you know you've taken, but can't locate. This is when good tagging practice is integral to workflow and ensures rapid recall of images when you need them. The more you tag the more used to it you'll become and figure out a system that works best for you, but also to build up numerous tags to make future tagging less time-consuming.
In Photoshop Elements 8, there are a variety of processes to help you tag, star and rate photos. The latter options are somewhat cruder and ideal for initial quick edits on the fly. Prior to this phase, however, all your images should be tagged, be they good, bad, ugly or otherwise - even images you don't think you'll ever use may come in handy in the future. Tags can be any words that you wish, though should include both broad generic terms as well as being more specific. For example, when reviewing all your pictures from a holiday in Nice, every photo could be tagged with ‘holiday', ‘Nice' and any other general tags that may be of personal value. Next, tags concerning technical terminologies should also be considered - ‘shallow depth of field', ‘blurry' or similar may come into use should you wish to browse this way in the future. Lastly the specific content of the images is keenly important, where descriptive terms such as ‘mountain', ‘family' and other content-specific tags will be of use. Elements 8 even goes an extra step further by not only automatically detecting faces in a scene, but recognising them too. It's possible to tag names of your friends, family and so forth and, once named, the program will auto-associate the facial characteristics of that person. Similarly, Elements also auto-detects image quality, where out of focus and similar issues are detected and automatically tagged.
The initial trick for keyword tagging is to list as many keywords as possible. Once a large database is added, the likelihood is repeat use of many of the words, which will all be readily available for quick and easy apply to images.