There are so many ways to configure Syncthing; it’s hard to know where to start. It took me a very long time to figure out how to be organised and I still have remaining mess that’s hard to cleanup. This is what I’ve settled on for now.
A folder on every device to send to every other device.
A central ‘backup’ server at home. Receive only.
This has been the missing manual for me. The key thing was realising that actually all devices are mobile and I needed that central server to simplify things, not for technical reasons but for my own understanding!
A SMALL folder that is shared with all devices. It only contains files about the same size as a text file. No media.
There are 2 main networks: Work and home. The central server is at home and stuck on 32bit. This means that if someone leaves a laptop at home, they’ll be no backup; only that small folder.
No syncing goes on over mobile networks. The work network is 3G only to the public internet so we have to be careful of that. Devices sync behind the wifi only.