Great tips for virtual presenters from Training Magazine
Take the phones/microphones off of "MUTE," especially when learners are paying for the class. Learners, by and large, want to be actively engaged in the learning process. If you are going to mute them, just e-mail a URL to the recording--I promise they won't watch it. Focus on the chat and feedback indicators (hand raises, emoticons, etc.). Ignore them once, just once, and learners will probably ignore you for the rest of the session--AND share their feelings with everyone else in the class. Remember, learners have e-mail, private chat, Skype, and Twitter to come up and slap you around (even DURING the session)--without you seeing it coming. Eliminate your verbal crutches. (Cool, gotcha, you know, umm, aaaaaaaaaaahhhhhhhhh). They make you sound less intelligent than you probably are.
Read the entire article here.