Also, remember your company identity and branding – you can afford to be less formal with your greeting if you are a company that is known for a more quirky, outgoing approach.
Listen to your messages and return your calls as soon as possible. Of all the lines of communication available (social media, text, email, etc.,) your callers resulted in picking up the phone to call you because they wanted to speak with a live person. Do them the common courtesy and give them a call back when you first have the chance.

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.
(in british accent) oh my god nooooo you’ve made me spill my tea you trotter !!!!! *running footsteps and random sscreaming* leave a message ill listen and call back when Im not busy beating my bloody siblings with a shoe.