Correct procedure for leaving a voicemail, in timeline order:
1. Say your name and, if applicable, your business or organization
2. Provide a number to call you back at
3. Provide a brief description of the reason for your call.
4. If applicable, provide a “need by” time for a return call.
5. Repeat callback number and/or provide honorifics if applicable.

Thank you. As you were. Suggestions for improvements to the above are welcome.