Some tricks worth thinking about: Seeing through the lies. Long pauses, short sentences, and frequent errors in diction or grammar can be a tip-off that someone’s lying. Here’s a more complicated system: Become a Human Lie Detector. Act truthful in one way and something else you do will betray you.
No system works all the time though. One problem is that the best rise to the top: Bill Clinton was famed as a good liar. Also, there are liars and liars. A genuine pathological liar, for example, is quite fluent and even persuasive if you let him distract you from the substance of what he says, which analyzed logically is usually nonsense.