After creating, the Voicemail Greeting, you can test it by calling to your number from another phone, and see if it is playing correctly or not. Open the Phone App. On the lower screen, tap on the Voicemail option. Select Custom, with this option, you can record the personal voicemail greeting on the iPhone. Tap Record, to start recording the voicemail greeting message on the iPhone. Greeting samples are given in this article below, Once you are done with recording, tap Play to listen. Lastly, if everything is alright, and custom voicemail recording is perfect, then tap Save.
You voice message greetings are supposed to be fun, energetic, and witty so that the callers want to pick up their phones and give you a call just so they can listen to the greeting again.

The bottom line is that a business’s situation is likely to change often and rapidly, each of which need a unique and applicable voicemail greeting to cover the circumstances and timeline. For example, callers shouldn’t reach a business-as-usual voicemail, and therefore expect a return call within the business day, if the subject they’re calling is out on vacation for two weeks. Such a lack of communication is a recipe to lose that caller’s trust and tarnish the brand’s reputation.
My friend found a recording of a man rifling off purposely confusing voice mail instructions. It's really fast, and he keeps saying numbers and number combinations... I wish I had it....