1. Never provide anyone any information on a call you receive. If you receive a call, go wit the expectations that it is a scam/spam. If it seems genuine, you call them back using a number from their website. Don't call back on a number provided by the caller.
2. Don't pick up unknown numbers.Let them leave a voicemail.
3. Most Govt. orgs or banks will not call you to request personal information over phone at least in the United States.
4. There are common scams/spams including Windows/Tech Support, IRS, You have won a vacation scam etc. Don't ever believe those. They are always a scam.
5. Never ever click/download a link/attachment on an email that you are not sure about.
6. Teach everyone how to read email headers if possible to verify the sender. It is too easy to spoof the from name/email. Fun fact: my wife recently received emails from ME (obviously not) asking her to wire money for some urgent need. lol. But she almost fell for it and I was shocked. The reason was email spoofing. I immediately showed her how to check the headers.
Most importantly, teach your parents or other non tech savvy friends/family to never trust anyone over the phone or email even if it seems like someone they know. Always be suspicious. It is ok to do so.
Oh and as the tax season approaches, the IRS scammers will be out in full force. Make sure that everyone knows IRS NEVER CALLS you especially to ask for money. IRS will always send you a registered letter in mail, always.