One of the factors that most frightens people when it comes to public speaking is eye contact. Speaking from my personal observation, using our eyes to engage and interact with the audience is just as important as having effective hand gestures.
Speaking in front of a group of people, having an engaging eye contact is usually manifested in giving each and every audience of ours a relatively same amount of attention by looking them directly in their eyes.
If we don’t give eye contact to our audience, we lose them. If we pretend to look at our audience by hovering our eyesight, in their direction, on top of their heads or on the background behind them, we confuse them.