Body language is a major portion of a speaker's presentation. In order to make any presentation effective one must learn how to use the body effectively. Here are a few important components.
Posture and Hand gestures
Your audience is looking for a confident speaker and you display that by your posture. The confident you look, the confident your audience is about you. Let your hands move and express your thoughts.
Using stage meaningfully
When you are on stage you own it and let your audience know that. Use your stage wisely and move freely but always keep in mind that those movements are for a reason.
Let your face show what you mean by giving expressions on your face that authentically display your emotions. Your expression is your connection.