Engaging in eye contact with your audience when speaking is the most important aspect of visual communication. Generally, listeners will keep their eyes focused on the speaker's eyes the majority of the time spent listening. Maintaining eye contact with your audience while communicating gives you a confident, authoritative presence. In contrast, if your eyes have a habit of shying away from the eyes of your audience, they will perceive you as uncertain or insincere, which will make the content of your speech much less effective.
The use of hand gestures while communicating allows you to emphasize certain points, and helps convey your emotion along with the words you say. Refrain from excessive or overly extravagant hand gestures, as this can distract the audience from the content of your speech and may make you seem less sincere about your words. Instead, use natural hand gestures that go along with the mood or emotion of what you are trying to communicate.
It is easy to forget about your own body language while engaged in communication with an audience. However, your audience will be perceiving every movement you make, even if subconsciously. Utilize authoritative body language to strengthen your communication, such as by standing upright and relatively still. In contrast, if you slump down or move about in a giddy fashion while speaking, your audience will perceive you as nervous, and therefore the message you are trying to communicate will seem less powerful and sincere.
When you are talking to an audience of multiple people, you have to be able to vary your attention between your listeners. This includes shifting eye contact among members of your audience, as well as learning how to speak to the entire audience while focused on one member. A useful technique is to focus primarily on members toward the middle or rear of the audience. This will make it seem like you are acknowledging the entire audience more so than when you are focused on the members toward the front. You should shift your eye contact between audience members in a natural manner while communicating, rather than darting your eyes between listeners.