A backup you have to remember to run is not a backup. Mine run every night at 03:17, when nothing else is happening: one copy to the external drive by the server, one copy encrypted to a small cloud bucket. Once a month I restore one random file from each copy, because an untested backup is a hope, not a backup.
The whole system is one short script and a cron entry. It has survived two dead drives and one spilled cup of tea. That is all I ask of it.