If you get repeated calls, you're already on a suckers list, so be extra vigilant. For the most part, these calls should be easy to spot for anyone, so all the usual stuff applies*
Email addresses are essentially in the public domain, so whilst there are suckers lists for email, most scammers don't bother, and just use one of the low cost 10bn addresses for a tenner type lists, some have more demographic data than others. Some even have things like postcodes, making it a bit easier for the scammers to hook.
Anyone who thinks they are above this are some of the easiest to reel in if its a more targeted attack, as has been proven time and time again.
*So:
Never, ever click links in emails, or call the number in an email (use the company's website to find the correct number).
Never call a bank etc back on the line they just called you on - use another line, or call a family/friend first, to ensure they haven't locked the line.
There is never a legitimate reason for hurrying you to do things instantly, this is a known technique to get the victim's brain into a state of panic, as used very effectively in retail "sales". If the deal/option is only available right now, its a scam.
If you see something too good to be true, speak it through with a family/friend first, as its pretty likely its a scam.
Assume every unsolicited incoming call/email is a scam.
Big egos are the easiest to fleece.