I do an automated nightly backup via restic to Backblaze B2. Every month, I manually run a script to copy the latest backup from B2 to two local HDDs that I keep offline. Every half a year I recover the latest backup on my PC to make sure everything works in case I need it. For peace of mind, my automated backup includes a health check through healthchecks.io, so if anything goes wrong, I get a notification.

It’s pretty low-maintenance and gives a high degree of resilience:

• A ransomware attack won’t affect my local HDDs, so at most I’ll lose a month’s worth of data.
• A house fire or server failure won’t affect B2, so at most I’ll lose a day’s worth of data.

restic has been very solid, includes encryption out of the box, and I like the simplicity of it. Easily automated with cron etc. Backblaze B2 is one of the cheapest cloud storage providers I could find, an alternative might be Wasabi if you have >1TB of data.