If it is not your turn to speak during the meeting, keep your microphone muted. Otherwise, your microphone will stream the sounds of your movements. This is especially important if you plan to eat during, tend to fidget loudly, or if your art supplies are making noise, i.e. brushes in a glass of water or kneading clay. These background noises can be very distracting. Skype has a microphone icon you can tap on to mute or unmute your microphone during class.