As your collection grows, a little structure goes a long way toward keeping things usable.
Consider organizing by category first, then by title or date within each category. A consistent naming convention — even something as simple as 'Title (Year)' — makes searching and sorting dramatically easier later on.
Periodically review older downloads you no longer need. Freeing up storage regularly prevents last-minute scrambles when you want to grab something new, and it keeps your library focused on content you actually use.
Finally, keep a lightweight backup of anything irreplaceable. External drives or cloud backups are inexpensive insurance against accidental deletion or hardware failure.