While Skype for Business meetings can be a lifesaver when your team isn't in a single location, there is a common behavior that drives everyone crazy… people not muting their side of the call.
This shows up in two different ways that are exceptionally irritating. Someone is listening into the call (and not presenting or interacting), and they're in a noisy location. Therefore, everyone else on the call has to listen to all that noise because they haven't muted themselves. The other is when someone has a headset, and the microphone is very close to their nose. You then get the "pleasure" of listening to heavy breathing until someone tells everyone to mute themselves (often repeatedly) if they're not speaking.
To mute yourself in a meeting, just click on the blue microphone icon at the bottom of the Skype display:
Once you do this, the icon (both at the bottom and the upper-left corner will have a slash through it, meaning you're on mute:
If you're listed as a Presenter in a meeting, you can mute someone else if they're ignoring your pleas to stop breathing. Look at the list of participants, and find someone with a light blue microphone icon that doesn't have a slash through it. That means that sound is being picked up from that person. Right-click on the microphone icon and you can mute them:
Bonus tip… if you're using a headset for your Skype calls, there's a good chance that it has a mute button somewhere on the device. When you press that mute button, it will also mute your Skype call.
Extra bonus tip… DO NOT PLACE YOURSELF ON HOLD WHILE IN A SKYPE CALL!
When you do that, everyone else has to listen to whatever hold message or music your device or organization might have. If you need to step away, just mute yourself.