I’d start with a clean, three‑tier tree: a root “Research Lab KB”, inside that a “Notes” folder for quick thoughts, a “Literature” folder for full papers and reviews, and a “Projects” folder for ongoing work. Under “Notes” keep subfolders by date or topic, under “Literature” split by year or source (journals, conferences), and under “Projects” create a folder per project with subfolders for drafts, data, and references. That gives a simple, expandable skeleton that lets you drill down without getting tangled.