I mentioned it in the Q&A of the course but thought, maybe it could help someone here as well, so I just repost it.
One thing I use when I only want to see the selected object(s) is with Numpad / (or View - View Global/Local).
This one great difference. If you would hide everything else and have old hidden objects (kept for safety) you will unhide those as well and have to hide them again separately. By using Numpad / nothing hides or unhides, so nothing is altered in the scene visibility.