So, how do you keep from losing data?
Do you mean how Shingled recording works? More or less described there. It reads the data, caches it, or re-writes to a empty section of the drive, then takes the data and re-writes the tracks so that they overlap again and are more dense.
The read write head can only write somewhat large track widths, but it is sensitive enough to read narrower ones. So it writes a track, then writes over half of it. It can read that data fine, but if it writes directly to the same area it would erase data. Instead it copies that data before erasing it.
When the drive is empty though, it can just put data wherever it pleases and would be equivalent performance to a CMR drive.
If you mean a personal question. I keep loose hard drives for making irregular system image backups of my other systems. And I tend to keep archived drives of older data that is a subset of my current data. Critical data gets backed up immediately to multiple systems and a USB flash drive.
I'm not much of a data hoarder though. My main backup drive is only 4TB. I don't bother backing up my gaming system except for my profile/account data.
I believe I have two 4TB, two 3TB, a total of 4TB of active SSDs, 2 old 1.5TB drives, a portable 1TB drive (also quite old). And a small pile of older 80-500GB IDE drives from old systems that I will probably test here before the end of the year and see what is good. 4 old 256GB SATA SSDs from various systems, all nice MLC drives that should last another few decades.