Lisa Evans has a great article at Fast Company about how to deliver a better speech. Her essay is titled, "4 Common Vocal Mistakes Leaders Make." She describes the following four errors:
1. They lack passion for their own ideas. They don't sound energetic and engaged. If you don't care deeply about your ideas, why should the audience care?
2. They speak in long rambling paragraphs. They forget to speak in concise sentences, with breaks to enable the audience members to process what they are hearing.
3. They are monotone. They don't use intonation to help emphasize key points, capture the audience's attention, and stimulate questions.
4. They fail to practice and then to listen to themselves speaking. Therefore, they have no idea whether they are delivering their message effectively.
I would add a fifth key error that leaders often make. Many leaders fail to use stories to communicate their key message. They rely on numbers, facts, and statistics. However, research shows that storytelling is much more effective when trying to influence and persuade.