How did you develop the final layouts and schemes in your last project?

In my last project, final layouts and diagrams were developed using UML diagrams such as class diagrams and sequence diagrams. I used tools like PlantUML and IntelliJ IDEA with visualization plugins for this purpose. I first created rough sketches, discussed them with the team, then refined the details and formatted them into final diagrams, which served as the basis for project implementation and documentation.