This iOS app does basically the same thing as the above method. It starts a call, initiates a second call, then merges the two so it can be recorded. However, instead of calls being stored in your voicemail, they’re stored in the app. Automatic Call Recorder Pro costs $4.99.
Recording voicemail greetings for your business or personal life requires a separate list of priorities, because they are being used for two distinct purposes and will be heard by two very different types of callers. I have a friend with two cell phones - one for work, and one for personal calls - and if you call both lines, you would never know it's the same person. While the message on his personal line might not be ideal, he took the time to record a professional voicemail message for his business phone, which makes it stand out.

6 Do’s and Don’t’s of writing Voicemail Recording Scripts Follows the do’s and don’t of leaving the correct voicemail for your clients. Write a new voicemail greeting for office following these 6 principles. A lawyer’s office needs to maintain professionalism at all times in order to record the perfect voicemail greeting. Let’s look at an voicemail greetings example.
Tap Voicemail, then tap Set Up Now. Create a voicemail password. Choose a greeting—Default or Custom; if you choose Custom, you can record a new greeting.