Rule 1: Be careful.! You can do a lot of damage when you are root/Administrator, data base admin, etc, so be careful.
Make backups. Pause before you press ENTER.
Make backups. Test wildcards before you use them.
Make backups. Pay attention to what you are doing.
Make backups. Don’t drink and compute.
Make backups.
Rule 2: Respect privacy.! Don’t look at anything that isn’t required for a task.
Don’t “browse.” Don’t look at something if you wouldn’t want someone looking at yours.