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.
The simple truth is that you need to be more aware of what you’re leaving for other people to hear. Sure, this doesn’t always register as a priority for users, but it’s never too late to reassess your greeting. a. Reading/Speaking in the Imperfect Tone: Tone is absolutely everything. Users don’t want to come off as being too nice, as it sounds insincere, or being too terse, as it can be interpreted as being rude. That being said, striking the right balance is absolutely essential. Your greeting exists as its own entity, and therefore, it should NOT rely on callers’ familiarity with you. Instead, it needs to appeal to the masses. As such, your inflection, i.e. the way you state your name and directions, needs to be both welcoming and firm. b. Injecting Humor & Insincerity: While humor/light heartedness can be welcoming, it can also convey a sense of informality, insincerity, and ultimately unprofessionalism. Why, because you’re not there to lend your humor or to contextualize. Instead, you’re assuming the caller has a working knowledge of your personality to ground the message. Though this might not sound like it’s all that terrible—it can be detrimental. As stated above, one should NEVER rely on a caller’s familiarity with you. Instead, aim to appeal to the masses. Humor is ultimately subjective, meaning not everyone has the same tastes; therefore, someone is bound to be turned off by a quirky or off-color remark. While implementing a light-hearted or even tongue and cheek tone can work, it’s just a really bad idea.

We put a lot of effort into trying to get people not to leave messages on the old house phone (long story, there was some reason I forget why we couldn't turn the voicemail off). Messages with words in don't work. Even if you make them 10 minutes long and full of "Please do not leave voicemail here, we won't hear it" repeatedly, people will sit through it and then leave a message. We eventually settled on something that sounded like a very noisy modem, which mostly worked. I have no idea whether people would recognise modem noises these days though, especially if this is for a mobile number...
Examples of Good Business Voicemail Messages. It makes a positive difference when you record a greeting message that adheres to the basic elements of good voicemail greetings. Here are some good business voicemail greeting examples: Hello, this is Jim Smith. I am currently on the phone servicing another client.