Prepare yourself using the ultimate voicemail script that’s always successful, then derive short queues for yourself to keep the voicemail on track.
To improve a a business voicemail greeting, keep these eight rules at the forefront of the creative process: Avoid turning customers off with overused and impersonal phrases like “your call is very important to us..." Avoid leaving customers unsure by not immediately telling them the business, department, and/or person they’ve reached. Avoid leaving customers confused with too many details and complications; just keep it simple. Avoid messages longer than 25 seconds. Do apologize for being unavailable at the moment. Do invite the caller to leave a message. Do tell the caller when they can expect a return call and actually follow through within that timeframe. Do tell the caller about any applicable alternative options of contact and information- website, live chat, email, social media, or emergency numbers. Voicemail Greetings 101

You should acknowledge that right off the bat by apologizing that they couldn't reach you directly.
Friends and colleagues speak to each using first names only. So do people of authority. They do not call each other and leave voicemail messages asking for Mister, Miss, or Mrs. Therefore, when you call a person you want to do business with and you leave a voicemail message, refer to them by their first name only. Don't say mister, miss, or misses. Don't say their last name. Begin your voicemail message by saying only "hi/hello" followed by the person's first name. Or, you can even forget the "hi/hello" and just say the person's first name. That is how you show confidence and authority and separate yourself from weak salespeople.