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.
It's easy to get carried away in a voicemail and include more detail than is necessary. We've all been in that situation where the automated or pre-recorded voice on the end of the line goes on and on with more information than you can take in.

It can be overwhelming to someone calling if your voicemail suggests they leave their name, address, time of calling, reason why calling, best phone number to call them back at, etc. They might not be prepared with all of the information and could end up leaving a confusing and flustered message. Instead, just kindly ask the person to leave their name and number and reassure that someone will be in touch as soon as possible.
From the Skype for Business desktop app (if you are running Click-2-Run build C2R 8201.1002 or later), select Set Up Voice Mail. Change your Call Answering Rules You can change what options your callers have when they reach the voicemail service; get disconnected, hear your greeting, record a message, choose to be transferred to the number or user you select. Change your prompt language This is the prompt language that is played to callers. For list of supported languages, see Languages for voicemail greetings and messages from Skype for Business. Configure your Out of Office greeting This is the customized greeting message that is played to callers when your status is Out of Office. This option can be activated "Always," when you have an active "Auto Reply" in Outlook, or whenever you have an out-of-office calendar appointment.