A key process in UX design is mapping User Stories, usually as post-its on a wall or table.
This could be a way to visually generate Epics and Stories. Map it out as cards, but then you've already got Epics and Stories defined and in the backlog directly from mapping it out. The post-its are "work items" (or epics if in the top row). Rows can be releases, or priorities (or some other new category...?).