This video gives an overview of how to use Google Assistant to swiftly schedule appointments. In order to effectively schedule appointments with Google Assistant with your voice, you need to speak clearly and evenly. Try not to speak with fillers like ummmm and ehhhh et cetera. In order to do this, practice articulating your full sentence first before saying it.:
You say in one go: "Hey google schedule an appointment for today at 4 PM meeting Mark"
You can also split up the command:
You say: "Hey Google"
Wait for Google Assistant to respond
You say: "schedule an appointment for today at 4 PM"
Wait for Google Assistant to respond
You say: "meeting Mark"