A custom phone greeting is a recording that plays automatically when a customer calls. They can be set to play right at the start as a professional welcome, as a voicemail greeting, or even as an away message when you can’t answer.
Using your cell phone to record a voicemail message isn't always easy. Between remembering what to say and getting the right timing, it's tricky. But your phone does have a playback option, and it's easy to listen to and review your message. For some people, though, cutting off the end of a message is a funny way to trick people and catch them off guard. In most situations, callers won't know it's intentional and will think you're far less than tech savvy. Definitely not an impression I'd want to make.

Avoid background noise. Whether you have music playing in your office, or you’re sitting in a coffee shop, background noise can make it difficult for your customers to understand your greeting. Limit the noise around you when you leave your voicemail greeting.
Your voicemail is important. Keep in mind, this is essentially one of the first impressions the hiring manager will have from you. You need to make sure your voicemail is as professional as possible. Whether you are trying to be funny, trying to show off your singing abilities or shouting in the car with the windows down, chances are the hiring manager won’t be impressed. Go into a quiet room and record a simple, “Hi, you’ve reached Kim Costa. I’m sorry I missed your call, but if you please leave your name, number and a brief message I will get back to you as soon as I can. Thanks!” You really can’t go wrong with this. Trust me when I say that hiring managers probably don’t want to hear your high school’s fight song.