How do you want to sound over the phone? Professional? Friendly? Calm? Confident?
Write down the words you’d like others to use to describe you over the phone.
Then call your own cell phone and leave yourself a message.
Research how to listen to your own messages (‘cause who does that any more?) and listen to yourself.
How’d you do? Were you:
If you didn’t like your tone, try standing up, sitting tall or smiling when you leave a message.
Do THAT when you answer your next incoming call. Your customers will appreciate it.