2."They never just say, 'I don't know.' Basically, if they're the type of person who always has an answer for everything, there's a good chance that — at least some of what they're saying — is made up."
5."Live by the concept 'Actions, not appearances.' For whatever reason, humans are terrible at predicting who is and isn't trustworthy based on outward looks alone, which makes honest and introverted people seem cold and scheming. So pay attention to what they DO, not how they LOOK."
12."Superficial friendliness. If you suspect someone may be faking friendliness, pay close attention to them when they walk away from someone else. You'll usually see the facade slip as soon as they think no one is looking."
15."If you're not that close and they gossip about other people to you, they’re definitely gossiping about you to everyone else, too. The only exception to this rule, of course, being your top BFF who you always complain with."