Use your regular, normal voice – not too excited, not too subdued. Talk how you’d talk on the phone with someone you like but who doesn’t make you nervous. Communicate ease without flippancy and importance without exuberance.
Increase the odds of getting a call back by mentally composing your message before each call. And remember, people hate it when callers state their name and phone number too quickly in voice mail messages – no one wants to listen to a message ten times to comprehend simple information. Begin by saying your name and company (if applicable). Then assume the person you’re calling doesn't have your number, so say your phone number twice. If your name is at all unusual, spell it the first time you say your phone number. Talk slowly like you were writing it down yourself. The second time you say your phone number, you can say it at your normal rate of speech. A gracious phone message is no longer than 30 – 45 seconds. Be pleasant, but also get right to the point. Keep your voice mail message to two points maximum. If you need to share more information, then say you will send an e-mail message with the rest of the details. Leave a specific message. There’s nothing more frustrating than a voice mail that says, “Hi, it’s me. Call when you can!” Even if you’re just calling to say “Hi”, tell them that in your message. End on a high note! You don’t necessarily need to say “Goodbye” at the end of a voice mail, because you didn’t really talk to anyone. Instead, try something like, “Look forward to talking* with you!”

With so much stacked against you, why bother? Because the responses to sales voicemails are generally of a much higher quality. What you lose in response rate will be made up for in conversion rate—if you know how to leave quality messages, that is.
“I followed your advice on how to leave voicemail messages that get more callbacks and since using it, my call backs have increased. But my question is, what do I do with the prospects that haven’t called back?”