The use of tags helps you and others find your media. This is especially useful once your media library grows. It will help you separate contents from different courses you may be taking or teaching. And for any published media, it will help generate the "Related Media" section, so that common videos with similar tags will appear here.
Below are some guidelines that will assist you on your tagging adventure.
If your media item belongs to a course or if it's for a course, you could use a course tag (e.g. 'INFO 3135 S10').
Use Tags liberally
Tags don't need to be a long summary or paragraphs. Short and sweet is good. But not too short. (For example, if I am creating instructional videos, it would be better off using "video tutorial" than just "tutorial".)
Don't create a tag that applies only to one post. The purpose of tags is to link related content together, not just label them.
You don't need to capitalize tags, as they get recorded in lowercase.
Be creative with your tags. Don't just duplicate the title or the category, think of something more creative.