There are two tiers of paid accounts, giving you ad-free access, the ability to “Slydial” multiple people simultaneously, and other premium features. For most people, the free version is perfectly adequate.
Follow the instructions and press that number. You will be asked to delete your current Voicemail greeting. Click on the ‘Yes’ button that appears on the screen if you want to remove that. You can save your new recorded Voicemail greeting or can use the default recorded option. From the home screen, select the Phone app. Note: Alternately, you can set up voicemail by selecting the Phone app then selecting and holding the 1 key. Select Keypad, then select the Visual Voicemail icon. Select Start. Select Ok. From any Home screen, tap the Menu key. Tap Settings. Tap Call settings. Tap Voicemail. Tap Voicemail again. View the voicemail number. Press and hold the 1 on your device’s dial pad to call and connect to your voicemail. Press the star * key to access the main menu. Press 4 to access the mailbox options. Press 7 to change the language of the voicemail prompts to either Spanish or English.

To record a call using your voicemail follow these steps: Open your Phone app. Click "voicemail" in the lower right-hand corner. Click "call voicemail" (depending on your carrier, you may have a different but similar option). Enter your iPhone voicemail password. Press the number associated with sending yourself a message.
My iPhone always seems to jump to voicemail before I answer it. I need to increase the call forward delay. By increasing the delay before the call is transferred to voicemail, I have a better chance of grabbing it. As expected, the caller will hear an increased number of rings before being transferred.