On Air Recordings recommends you order professional voicemail greetings through their site, then describe the tone, approach, or voice direction you’re going for.
Creating a professional voicemail greeting isn’t complicated, but you need to keep a few things in mind to ensure success. The following tips will help: Be friendly and welcoming - let your company's personality shine!; Have a clear voice, speak at a slow to moderate pace, minimize background noise; Ensure the greeting is human and approachable; Keep the greeting short and informative; Ensure the greeting doesn’t sound robotic or unnatural; Show your gratitude for the call by saying thank you; Manage expectations by clearly stating when the client can expect a callback.

“Hello! You’ve reached the voicemail of [your name], [your job title]. I’m currently either away from my desk or on the other line. Please leave your name, telephone number, and a short message after the beep, and I’ll be sure to get back to you as soon as I’m available.”
No44: Steve has been captured by a flying saucer and can't come to the phone right now, but if you leave your name, phone number, and a message, I'll have him call you back as soon as he gets away. Read all about it in next week's National Enquirer.