Expanding on the simple approach above, let the caller know who they've reached. This will not only eliminate people leaving voicemails by mistake, but it will reassure the caller that they have called the number they intended.
State your name clearly so the caller knows they have the right number. 3 of the messages I heard last month were missing his/her name.

It’s a good practice for each of your team members to have their own personal business phone numbers. There are many reasons why they shouldn’t use their personal cell phone number for business, so you’ll want to give them their own phone number through your VoIP provider or phone system.
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