Simply speak into your phone or computer while recording a greeting with your business phone service. If you need to create your own audio file, the voice memo app on your phone should do fine.
I have a confession to make: I haven’t recorded a new voicemail greeting since 2014. In the past four years, I (hopefully) have become more articulate, poised, and self-assured. But hear my voicemail recording, and you’d think I was still new to the work world, a little unsure of myself — and probably not an authority. Obviously I need toupdate it. And if you haven’t changed your voicemail greeting in over a year, you’re likely in the same boat. After all, a professional voicemail recording boosts your credibility, makes you seem more competent, and encourages whoever’s listening to it to continue the relationship. A relatively unprofessional one — like mine, for instance — does the opposite: It encourages prospects, recruiters, and potential connections to run in the other direction. With that in mind, I’ve written 18 unique voicemail greetings for every situation. Pick your favorite, practice a few times, then record your new voicemail.

Another way to make up funny voicemail messages is to act like a device has come alive. For instance, you could say,"Hello, I'm Bob's hair dryer, and I've taken over because I'm way more interesting. If you'd like to leave a message for him and have your hair dried at the same time, just hold up the phone." Answering like an answering machine, a microwave, or refrigerator and using the functions of that device in the answer are easy ways to create a fun voicemail.
Liam Neeson has been acting for decades but it was his recent role in the hit movie Taken that caught the attention of a younger audience. A self-proclaimed “first fan ever,” politely asked Liam on The Graham Norton Show to record her voicemail message greeting. Being the great guy that he is, the star humbly complied but added a fun and unexpected close to the recording.