Tone - select the right tone for your business brand. If your target market are young millennials, then the script would most likely include some slang words, be quite laid back and the script would be recorded in an energetic tone. If you primarily service the business market, then the script would be more articulate and recorded with a more professional tone.
Now that you know which script to use, how do you record it? Depending on your budget and the resources available to you, you can record the script yourself, use a text-to-speech program, or hire a professional voice actor to record your greeting.

VirtualPBX provides every extension owner in your company with custom routing. If the employee isn’t available, the call will go to the personalized business voicemail account for that employee as a result. In this way, each employee can have a business greeting for callers. Similarly, you can set up voicemail boxes for departments or your company as a whole. Even if the call goes to a phone that already has personal voicemail, we can make sure your business calls only go to your business voicemail system. People that call the employee’s number directly get personal greetings, those that go through VirtualPBX get a business greeting.
Writing a script doesn’t mean you have to write a speech. A simple greeting is fine, like this sample voicemail message: