Back up with Time Machine

Automatic backups and file-by-file restoration.

1. Plug in an external drive (at least 2× the size of your data).
2. System Settings → General → Time Machine → Add backup disk. Tick "Encrypt backup".
3. Start a backup right away and list existing ones:

   tmutil startbackup
   tmutil listbackups

   Copy
4. To restore: open the folder concerned then Time Machine → Browse backups.
5. When setting up a new Mac, Migration Assistant can restore the whole backup.