Traditionally, there are seven action bonii, each announced on the half-hour.
Like everything else, coming up with a good action bonus is a matter of inspiration. A good action bonus should both require the knowledge of some piece or area of trivia to be performed well, and invite varied and creative interpretations. As with other bonii, you should strive to cover many fields of trivia with the topics of your seven actions.
Some of the most popular action topics are things that are patently impossible to reproduce, thus straining the imaginations of players. Traditionally, at least one bonus invites musical performances of some kind. Actions that invited nudity or minimal dress were once quasi-tradition, but have waned recently.