When you’re looking for a job, a good rule of thumb is to answer your phone as often as you can. You never know when a recruiter might be calling to set up an in-person meeting, or conduct a phone interview.
Keep it Brief. Time is money in business, so if your voicemail is long, chances are the caller will simply disengage before the cue to leave a message even sounds. Keep your voicemail short. The most should be around 30 seconds, and even that’s pressing it. We’ve grown into a country where our attention span can last only about 10 seconds in some cases, so keep it short, brief and to the point. Persuade and Engage the Caller. If someone calls your business, they already have an intention. It’s the quality of your voicemail that plays a factor if they consider you a company they’d like to deal with. This is your chance to motivate someone to engage in a meaningful conversation with you. If your voicemail is shoddy, chances are they’ll hang up, or lose motivation to continue the call. In other words, your voice mail must engage and entice someone to the point that they care enough to leave you a message.

7. A Classic Hepburn Answering Greeting for Voicemails. Katharine Hepburn’s iconic and feisty voice goes down in history and can add a bit of moxie to your voicemail greeting.
When leaving your voicemail and phone number, do not say, "Please call me back at ..." Nothing sounds more like a salesperson making a cold call then saying, "please call me back at...".