We all have at least one random key without a label, and we have no idea what it opens. Today, label all those spare keys. If you are not sure what they open, label them “? 1/13/25” then in a year – if no ID you can toss. This zipper pouch keeps keys organized. These are the key covers I use; the color coding helps me reach for the correct key. For spare keys I use these tags.
My trusted neighbors and I exchanged keys, instead of their home address, I used a code to label their keys, that way if someone who should not have their keys gets them, they won’t know what they open.

You can also repurpose the plastic tabs from bags of bread as key labels, like this:
