Test your microphone prior to conference. Jimi Hendrix may have been able to use feedback effectively, it's more likely to deafen your colleagues however and won't get conference off to a good start. If you do get feedback play around with positioning of your speakers and microphone until you find optimum position. Clothing

Your company may be relaxed regarding clothing but try and remember camera. Bright colours and patterned clothing don't help transmission. Instead try and opt for colours such as blue or grey.

Lighting

Consider effects of lighting on camera. Up lighting is generally considered best and should be in front of participants. Also beware of windows in camera shot. If windows are in shot try and use curtains or blinds to prevent glare ruining shot.