Model the data flows in a paper-based solution.
Many mature business practices stem from paper-based solutions. Kanban worked on paper cards, ticketing systems worked on paper tickets, async queues worked on mail trucks and in/out boxes, ‘cc’ line in email stands for carbon-copy.
If you first model a system and it’s dataflows using paper, you aren’t distracted by the technical details of the solution. It’s easier to see how the data will flow, and who will do what when you model the system using only paper. Then reflect that paper system in tech.