Before giving a speech, you must do several practice runs (at least three times). Record your practice runs, and carefully observe and study your posture, body and head movements, hand gestures, facial expressions, and eye contact with the audience. Hear for your tone, inflection, and volume of voice. Note and adjust the cadence, such as rhythm and speed of speech. Determine when it is appropriate and effective to have short and long pauses. Pay attention to the clarity of your spoken words and pronunciations. Analyze the logic of information flow from the perspective of your audience, who may or may not know full context and overarching purpose and message of your speech. Make adjustments, practice, and repeat. Once you deliver your speech, obtain the video/audio recording if available and study it carefully.
As you practice to become a better speaker, carefully observe and study the speeches of great leaders and speakers. There is so much everyone can learn from great leaders and speakers, their speeches, and their command of the moment. Great leaders and speakers have worked on their craft for a lifetime, and their speeches are lessons that should be studied by all.