Earlier quoted context omitted.
Key phrases make sense to put in place, but another easy safeguard is: "Before you send anything to anyone, ever, call them back. Doesn't matter if it's me, the bank, a lawyer, whatever... tell them 'hang on I have another call coming in, let me just call you back in a few minutes, okay?'"
Not a thorough safeguard, if scammers have half a brain cell they can provision a VOIP number for such a request. They’re nothing if not accommodating.
This is a very useful precaution for banks, and for or calls that come from a family member's real phone number.
But scammers will just open with "I'm in trouble and my phone died" or "I'm in jail calling from a pay phone" and calling back won't do anything to help with that.