7.keep it interactive.
Social scientists have demonstraed that an interactive audience is more easily persuaded than a passive one. In many circumstances the give and take between speaker and audience breaks through the reticence and reserve of listeners,encouraging them to engaga with speaker and play a part in the proceedings.
We see this in certain churches using the call and response tradition of worship. We see it in school and universities where an effective teacher by asking questions can get monosyllabic students to open up and participate.
And of course the would also witnessed the power of audience interaction in the massive rallies of Nazi germany when Hitler would cry "Sieg" and the soldiere replied "Heil" raising their arms in the Nazi salute. I include this negative example because it is a powerful reminder that what makes a speaker a dangerous demagogue is not his technique but his moral purpose.