Keeping Layer Names Useful Across a Long Illustration File

I am working on an illustration file with many layers for background shapes, characters, lighting, and small details. As the piece grows, names like Layer 12 and Group 7 make navigation slow, and I lose track of which elements are final. I want a naming system that stays readable when collaborators open the file, while still being quick to maintain while drawing. I currently group sections by scene area, but nested groups make the panel long and difficult to scan. What conventions do you use for prefixes, color tags, or folder structure? I am especially interested in ways to mark approved, draft, and reference layers without creating clutter. If you have a workflow for flattening temporary layers or exporting a clean handoff version, please describe it. Examples of your naming patterns would be helpful, along with any habits that prevent the structure from breaking down during a rush.