If you want to be a liar then you have to make sure not to be detected. You have to make sure you do everything normal like your telling the truth and even your heartbeat has to stay normal. Heartbeat and body temperature(sweating) is how lie detector works. Keeping your breathing and thinking in a normal way will make the lie almost real; believing in your own lie will make it believable to anymore. also keeping your eyes on the person not always looking down will make you look like your telling the truth.
If you want to be great at being a liar you will have to study the ways people use words and how they get into a persons feelings. you have to know how to brainwash someone to believe what you want them to believe.
No,it isn't needed; this blue sky, the two exact trees
Where they are green ash, blue pine. The seas can rise
To within an inch of the buildings but not,
Ever. For now, like them, my words can be trusted.
There is no need for a doubt. We will not die.
We cannot keep the wood from receding north
To a cooler horizon. Red, white, and yellow
Trash will escape our hands to go into the water.
A glowing, new coal will escape our lips and go down
Through time in the water, to come up a cool, gold
Drink. The truth: We aren't eager to die. We
Turn all our acts to good. We complete. We don't
Let our anger loose. All earth
Is as wide and dear and clean as when I was small.
Whenever I lie, I tell a truth.
AND
If you tell the truth, you don't have to remember anything.
Mark Twain
(1835-1910, American humorist, writer)