Hey team,
I put together a keyboard hotkey to mute and unmute myself during Skype calls using Alfred even when Skype is running in the background.
Hotkey: Control + Shift + \
Screenshot:
You can easily modify the hotkey to another combination of keys if you wish.
Download Link: https://www.dropbox.com/s/6abvwywh6yrva1h/Skype Mute on%3Aoff.alfredworkflow?dl=0
Kudos to FroZen_X for what this workflow is based on: