Besides having good speaker and microphone or a good headset (recommended), i think you should find a quiet place to carry out the session. Skype also instruct users to have better call quality, if it says your mic is too loud that means either your voice is too loud or you have overwhelming background noise, the programn will automatically fix the problems by adjusting the settings (if you tick in the box automatically adjust setting)
Sometimes, there are some problems with the network connection (skype also notices you this) and you may not be able to hear what the volunteers say or their voices are constantly interrupted, try to turn your modem off and turn it on again to see if it helps. Otherwise, we will have to endure this problem or if the call quality is too low to continue, we're forced to cancel the session as this type of problems is uncontrollable.
