“Good afternoon. You have reached the office of [your name]. I will be out of the office beginning on [date] and will be returning on [date]. Please leave a brief message with your contact information, and I’ll be sure to get back to you as soon as I return on [date]. If this is an emergency or you need to speak with someone before I return, please contact [name of colleague/supervisor], [their job title], at [their phone number].”
It's as much a truth with residential phone service as it is with business communications, though those numbers are much lower. Voice over Internet Protocol (VoIP) phone service provider Vonage reported in April that voicemail deposits among its residential customers had dropped by 8 percent since October 2013, and retrieved messages were down 14 percent.

Keep it simple, concise and to the point. Callers won’t need your life story, and won’t want to wait around for a 2-minute greeting to end just so they can leave a message. Don’t hide the details, tell them where you will be, when you will be there, or when you won’t be there, and how to get in touch.
Since I pride myself in being responsible, if I don’t receive a return call I have to assume I wrote down wrong number. If I were irresponsible I would just blow it off and not care. But if I wrote down the wrong number I have a responsibility to get a hold of this person. This extra work combined with wondering if it’s the right number, leaves a bad taste in my mouth.