Great advice! I like to pair that with a healthy dose of "don't try to fix anything until you understand the problem." Too often I've seen engineers flail about trying to resolve an outage by issuing commands at a rapid pace, but this rarely addresses the problem. It may look like they're busy and engaged in troubleshooting, but it's really just thinly-veiled freaking out.
Take time to understand what broke, develop the solution, then implement. Bonus points if you go the extra mile to take the fix out and confirm that the problem re-appears. That's the only way to be certain you've fixed the issue intentionally.