These are just a few ideas to get the gears turning. These are simple examples, but don’t be afraid to show a little personality.
1. Write a list of information you want to include in your voicemail greeting. Writing out a list of points to include may sound arduous, but when your voicemail could potentially be the first impression someone has of you, it’s best if it doesn’t come with a bunch of "Um, uh," noises and awkward pauses. You want your voicemail to contain some basic information in a polite manner that will help the caller know that it’s you, and information to leave so you can call back as soon as possible. Include your name (and the company if this is a business voicemail), a statement that lets the caller know you apologize for missing the call, and information you would like from the caller such as name, number, and a brief message concerning the purpose of the call.

Practice your spiel so you can speak with authority. This lets the caller know how confident, qualified, and prepared you are. The goal is to sound like you’ve been doing this for years, not a few minutes.
Users often don’t invest enough time into their messages, resulting in incomplete, unprofessional, or otherwise under-whelming greetings. Sure, crafting a greeting doesn’t sound all that complicated; however, there are a number of pitfalls users can fall into—i.e. informality, terseness, sincerity, lack of direction, and more. While none of these sound too catastrophic, they are often interrelated. As such, they tend to worsen any problem. For example, humor can cause informality, worsen ambiguity, and weaken sincerity. That being said, users should strive to avoid ALL these pitfalls.