Try to stand while you're speaking
If you must sit down, compensate for the dampening effect on your voice by sitting up straight, with your feet flat on the floor, and breathing deeply.
"The camera and microphones exaggerate everything," Weiss adds. So maintain a more formal posture than you would in person and "don't slouch."
Speak slowly. Pause between ideas
"In person, many executives tend to speak rapidly," Weiss notes. "But in a conference call or teleconference, it's crucial to give people time to absorb what you're saying -- especially since, if you can't see them, they may be multitasking while you're talking." Leaving a pause between the points you want to make gives listeners a chance to comment or ask a question, which leads to the next tip:
Keep it collaborative
"Too many virtual meetings are data dumps, where one person dominates the discussion -- usually the highest-ranking person," Weiss says. "It's frustrating for everyone else, and it's dangerous, because if you give people no opportunity to comment, you really have no idea whether they understand you or not."
One way to make sure everyone has a chance to speak up is to appoint a host or moderator who will chime in and ask attendees for their views. (This also has the salutary side effect of discouraging too much multitasking: No one wants to be noticeably not paying attention when called on for a comment.)
The biggest reason not to hog the limelight, Weiss says, is that "many deep thinkers are not assertive enough to just jump into the discussion. Someone may have the answer to a problem you're trying to solve but, by not pausing enough and not asking for input, you miss it."
In that respect, at least, virtual meetings are no different from the in-person kind.