The first and most important tip about how to improve the presentation of your sermon is, be natural. No technique can surpass the importance of being natural. Learn, improve, progress, but when you speak, be yourself.
Express yourself with clarity
Pronounce the words correctly. As you speak each word with accuracy, your expressions will be enhanced and the message will be better understood by the listeners. Practice exercises to improve your diction: experiment reading in a loud voice, placing your finger or a pencil between your teeth and speak as clearly as possible.
Speak with resolution
Use the voice at an appropriate volume to your surroundings. Always speak with enthusiasm and sincerity, for if you don’t demonstrate that you believe in what you say, the people who are listening will show far less interest in your talk.
Vary the pace
Do not speak too fast, because people might have difficulty understanding what you say. And don’t speak too slow, because you may sound monotonous and tiresome. Alternate the pace of your speech; this will help to keep people’s attention. Practice at home, recording your lecture and then listening to it. This way you will be able to evaluate and improve the rhythm of the presentation.
Pay attention to the language
Use appropriate vocabulary. Avoid vulgar terms, slang, or banal words. You should also be careful when using unknown words. Pronounce them only when strictly necessary and try to explain their meaning. If you are speaking at a public conference, avoid Adventist jargon and terms that the non-churched may not understand.
Use correct grammar
Common grammatical errors may hurt your presentation and even damage your influence. Be careful with verb agreement and the correct pronunciation of words. Try to read good books and observe how each author builds sentences. Reading is one of the best ways to learn how to speak correctly.
Practice good posture
Do not put your hands in your pockets or behind your back while you speak. Keep your arm free and avoid excessive gestures. It is preferable not to gesture than to gesture too much. Distribute your body weight on both legs and avoid leaning on one leg only. Also, do not move around too much. Move around only when you are emphasizing an interesting point. Do not simulate arrogance or humbleness. Be coherent with your facial expressions: smile when appropriate and do not talk about happiness with a gloomy face. Also, avoid reading long passages in public.