Past, Present, Future. This will give you an immediate beginning point and logical flow.
Analogy. Use a separate example to explain an idea about your topic.
Point, Reason, Proof. State the point and show reasons why it is true. Go on to add proof to each reason you give and summarize these points in the conclusion.
Problem, Cause, Solution. Ask a question, “Why this?” Describe the problem and explain why it is a problem. Conclude with a solution.
Advantages, Disadvantages. Explain how the topic is good or beneficial, and how it may be bad or harmful.
Build impromptu speaking skills in an low-stakes, high-interest activity. Try Tabletopics, or have students create daily of weekly discussion questions.