Think through what you are going to say before you place the call. When men hear the beep, they often freeze up and forget what they wanted to say. If you want to be the go-to guy at work, then you have to exhibit competence on all levels. Don’t spoil your confident image by hemming and hawing and filling your messages with “uhhhhs,” and “ummmms.” If it’s a really important call, consider writing out what you want to say beforehand. If the person picks up, great, you now have some notes to remember what you wanted to talk about. If they don’t answer, you can leave a clear and concise message.
With Visual Voicemail, you can see a list of your messages and choose which ones to listen to or delete. Learn how to set up and transfer your existing voicemail. Create a voicemail password, then tap Done. Enter your password again to confirm it, then tap Done. Select Custom or Default. If you choose Custom, you can record a new greeting. Go to the Phone app, then tap the Voicemail tab. Tap Set Up Now. Enter your password,* then tap done. Record a custom greeting or use the default greeting, then tap Save.

Additionally, you will want to close out your voicemail by (re)stating your contact information and name and purpose of your call. This is another little trick of leaving voicemails - people tend to remember the first and last things you say more so than the middle, so by summarizing the important pieces of your message at the end, what you said is more likely to stick.
Remember, the idea is for prospects to want to talk to you. Your tone can make or break the voicemail. So, remember, you’re not bothering them — you’re enlightening them. If you have a purpose for calling, you’re never going to trouble them.