For each event that you will be promoting, you should analyze every advertising option and use ALL that apply. Do not simply settle for using some of those that apply to promote your event. There is a difference between the words promotion, advertising, and publicizing. Publicity is using those options at your disposal to advertise your events that require no monetary outlay. Conversely, advertising consists of methods that require spending money.
Promotion is all of the above and everything else.
The types you choose to use will depend on what information you have on the program and the audience you want to attract. For example, posters inform the public of the program's existence including who, what, where, when and how much. News releases to print media include the obvious and further educate the public about the program and its content. All promotional materials should build the reputation of the program and the supporting organization. The ultimate goal is to maximize program attendance.