I use Adobe Photoshop Lightroom its a photography software program developed by Adobe, designed to assist photographers in managing digital images and doing post production work. It is not a file browser but rather an image management application database which helps in viewing, editing, and managing digital photos. When you start to get a lot of images in Lightroom, you will want to search and categorise them for all sorts of reasons. Keyword lists for Lightroom are TAGS that are embedded in the EXIF data in images. EXIF stands for Exchangeable Image File Format, and is a standard for storing interchange information in image files. The EXIF data can be viewed using image editing programs. Alos Flickr and other photo sharing online communities display EXIF data (if available) alongside images, that also means that you can peek at the camera settings used by professional photographers and this is a very valuable learning tool. So why use keyword lists in the first place? Well, auto completion is a good reason, as it saves typing. Also when you run through a specific structured list, it helps keep your keywords tidy. Photographer Nick Potter has created a set of free Keyword lists for Lightroom. The lists cover Geography, Animals, Colours, Natural Landforms and Bodies of Water. While not proclaimed as a comprehensive list, it id FREE and you need to buy a more comprehensive list from say, the Controlled Vocabulary created by David Riecks for example.
I use keywords and looking at your categories can tell you a lot about the photos you take. I end up with a list of categories, all which do contain from 5 to 30 sub categories along the following keywords
[Animals] - [Art] - [Buildings] - [Colour] - [Family] - [Festival] - [Food] - [Geography] - [Photography] - [Plants] - [Season] - [Sky] - [Sport] - [Technology] - [Transport] - [Water]
Of course if you want to sell your images as stock photos you could use these keywords to make your images more easily indexed and found by perspective buyers.