Ben,
KK's description is exactly right.
I use a number of different types of notifications.
1- First one is as simple as a 1 line process that sends a test email to SystemSettings (which I always define as an intelligent in my BSVs). This process allows me to easily test the outgoing email functionality of the BSV as well as the workings of any outgoing email server that the email is being sent through.
Process: SEND OutgoingEmail_Test TO SystemSettings
2- Most of my outgoing notifications do exactly as KK describes and pull selected info from existing BOs to populate the notification attributes before sending.
Tom