Stay Synchronized
Syncthing is one of those set-it-and-forget-it services. It handles peer-to-peer file synchronization between my devices without needing a central cloud provider.
Deployment
I mount a large external drive (/mnt/toshiba/sync) to handle the heavy lifting of my photo backups and documents.
Why it's better than Dropbox
No subscription, no limits (other than my own drive space), and it encrypts everything in transit. I mainly use it to sync my camera roll from my phone to the server, which then feeds into Immich.