As I was taking in each of the points, I was thinking to myself, Yep...yes...that seems true...yep! At a certain point, I grew weary and thought, OK, this can end any time now! In my experience, people are not willing to read long articles, never mind put in the consistent work it takes to master a long list of skills such as this one.
It reminded me of my upcoming book about avoiding bad habits, which includes a section entitled "Getting out of your own way." There are many times in life when you can put tremendous amounts of time and effort into learning, creating structure, and meticulously building many new habits. Or you can relax, focus, and "do the right thing" on the fly, without making such a big project out of it.
For example, you can learn all of these tips for spotting liars, such as understanding that people often look up and to your left when imagining a scene (constructing a visual lie) and level to your left when imagining something heard (constructing a lie about what was said). You can spot the times when someone is smiling but their eyes aren't (they remain still and emotionless). You can work really hard to notice when there's a gap between a facial expression and a verbal one, or when liars do or do not use contractions to explain a situation.
Or! You can learn how to observe well and notice when something doesn't feel right. If it doesn't feel right, don't trust it.
For example, If you're relaxed and paying attention, you'll notice a creepy feeling when someone's mouth is smiling brightly but their eyes remain emotionless. You'll notice the difference between someone giving you a direct, genuine answer and someone over explaining things or answering questions that weren't asked. Your heart and gut will tell you that something's up!
You may not know exactly WHAT is up, but you don't have to know. Your gut feeling is the only red flag you'll need to withhold your trust until you can sleep on it or do some more investigating.
To increase your ability to notice and "feel it" when people are lying without having to become a masterful Truth Detective, dedicate yourself to mindfulness meditation, which increases your ability to pay attention to what you are feeling as you're living your life. Learn what a lie feels like, and then follow your feelings.