Recommendations for data backup solutions ?

Hello, so, I have been self-hosting some basic stuff recently, including data storage so i don't have to rely on external services like google drive.

It's working fine, but I wondered what would be the best backup solutions in case something unexpected and unfortunate happens (accidentally wipe out everything, drives dying, electrical issues, house burning down, that sort of thing).

I was wondering if more experienced self-hosters had recommendations about that ?

Maybe storing a physical drive in an especially sturdy box ? Perhaps using distant cold storage solutions ? Or even something I have never heard of ?