Everything that matters, briefly.
BEFORE INSTALLING
Check requirements against your plan Check the project is actively maintained Download from the official source only, never a site offering premium software free
INSTALLING
Dedicated database and user
Correct permissions: 755, 644, 600 for configuration
Delete the install directory Change default credentials
CONFIGURING
Debug off, errors logged SMTP for email Cron job where needed, remembering HTTP wp-cron is blocked here Backups off the server Admin area protected
MAINTAINING
Update weekly Scan monthly Remove what you stop using, properly Test a restore occasionally Keep a record of what is installed where
THE THINGS THAT CAUSE MOST PROBLEMS
Nulled software Not updating Abandoned installations left in place No backups Email sending unconfigured
THE TWO HABITS THAT PREVENT MOST OF IT
Apply updates. Verify backups.
Everything else is refinement.
