Users often don’t invest enough time into their messages, resulting in incomplete, unprofessional, or otherwise under-whelming greetings. Sure, crafting a greeting doesn’t sound all that complicated; however, there are a number of pitfalls users can fall into—i.e. informality, terseness, sincerity, lack of direction, and more. While none of these sound too catastrophic, they are often interrelated. As such, they tend to worsen any problem. For example, humor can cause informality, worsen ambiguity, and weaken sincerity. That being said, users should strive to avoid ALL these pitfalls.
11. Hello, you’ve reached [your name]’s cell phone. I can’t take your call at the moment, but if you leave a brief message, I’ll get back to you as quickly as possible.

There is no definitive answer here, but you should include one of the two at the beginning of your message based on what makes the most sense.
For users who want to avoid the scripting process altogether, there are also services that provide prerecorded messages. Again, your voicemail greeting shoulders a lot of responsibility. Some people aren’t comfortable with having to create a message to deal with it. As such, users can choose from libraries of prerecorded messages, which are standardized greetings, for their voicemail. There are a variety of applications, services, and companies that provide this service. For example, VoiceNation, a voicemail, virtual PBX, and answering services provider, offers users a variety of samples.