"The voice prompts and hold recordings we received from On Air have been well received by our customers and staff. On Air's voice talent has proven to be a great fit with our brand, and they made the recording process as smooth as possible." - Adam Rawlings, Proposal Writer/Marketing Support, G4S Canada, Toronto, ON
If you are going to be unavailable for a predetermined time, let people know. Example, if you are on vacation for the next two weeks, inform your callers in your greeting that you will be returning calls on such and such date. This way they expect it to take a couple of weeks before you get back to them instead of stewing over why you haven't returned their call.

Avoid any confusing nicknames – Introducing yourself by the name you are most commonly known as and give your full name if the callers aren't likely to know you personally.
VirtualPBX provides every extension owner in your company with custom routing. If the employee isn’t available, the call will go to the personalized business voicemail account for that employee as a result. In this way, each employee can have a business greeting for callers. Similarly, you can set up voicemail boxes for departments or your company as a whole. Even if the call goes to a phone that already has personal voicemail, we can make sure your business calls only go to your business voicemail system. People that call the employee’s number directly get personal greetings, those that go through VirtualPBX get a business greeting.