The national Propaganda Tournament Rules call for four sections of Propaganda to be played each year. Practices consist of explaining each section and then reading sample examples from that section. (A set of hundreds of past questions for each section is available for order.)
For younger players or new players at any level, you may want to break each section in half. Cover half the techniques of a section (and not necessarily the first half–you could group them any way you think is best) and then read examples of just the techniques covered. Then repeat the procedure (explanation and examples) for the other half of the techniques for that section. Finally, read examples from any of the techniques in the entire section.