For contacts, you can export them as vcf using simple contacts or the likes and back them up in backups folder. Setup a sync between your pc and phone using sy

For contacts, you can export them as vcf using simple contacts or the likes and back them up in backups folder. Setup a sync between your pc and phone using syncthing and select folders like backup, photos, videos and whatever else you want. I use this and find it pretty convenient after setting up. Also, there is no server involved as the sharing is peer to peer.