A good speaker-
– is lively, enthusiastic, interested in the topic and considers it vital to the audience and so speaks with enthusiasm;
– has a sense of responsibility to the audience and tries to say something that will be worth the listeners time;
– has a sense of responsibility to the others in the program and, if allotted 5 minutes, doesn't squeeze others off the program by taking 10 minutes, shows respect of what they may have to say;
– has a sense of responsibility to the subject, doesn't speak on something he/she doesn't know;
– has a sense of leadership, stands tall, makes eye contact, speaks responsibly and with authority, is positive, friendly straightforward
– keeps head on shoulders, doesn't let confidence turn into overconfidence
– can accept feedback and benefit from it.