Talk about the user’s journey through your product by building a simple model that tells your user’s story as you do. It turns out this simple idea makes working with user stories in agile development a lot easier.
At the top of the map are "big stories" (alternatively user activities) - something that has lots of steps but doesn't always have a precise workflow.
A story for an "activity" might read: As a consultant I want to manage my email so I can keep up with clients, colleagues, and friends. But that’s way too big of a story to put into an iteration or sprint.
That story breaks down into other stories like "send message", "read message", "delete message", "mark message as spam" – stuff like that. I call these user tasks. (Again a word used by UX people.)