Be prepared. If you need to leave a complicated message, think it through before you call. That way, you won't sound confused and the recipient will understand what you need from them.
From me to you. Identify yourself and the intended recipient. A message for no-one in particular is a message deleted. Use first names if appropriate, but 'Hey there, big guy' is not on – voicemail might be checked by others.
Be concise. State the reason for the call first, then keep to your key points. Your footie team's current prospects can probably wait until Friday night.
Say it clearly.Speak slowly. Repeat your phone number. And spell out your weird surname.
Let your manner fit your message. Always be polite and professional. Remember that you can hear a smile, but don't grin if you're delivering bad news. Laughing as you let your boss down won't help promotion prospects.
Location, location, location. It's no use shouting a message over a train station Tannoy, so call from a suitable place. 'The 12.15 to Paddington departs from platform four' generally makes for a confusing message.
Wrap it up. When you've finished, you've finished. Blathering on about the weather, holidays or who you bumped into in the restaurant yesterday is not required. Instead, a simple 'OK, bye' implies that you're busy and that you mean business.