Chew gum if you are nervous-Due to Evolution Process in humans, while eating, our brain perceives that it is not in any immediate danger so the ability to retaliate or fight is weakened.
Give something to get something – Cialdini also found a very strong law of reciprocity. Give something to get something. It isn’t just with quid-pro-quo, do this even in your daily life: Give someone a compliment and they’ll feel a desire to have a better attitude toward you. It also works in the negative: if you have a big ask, then back down to a smaller ask, they’ll be more likely to comply because it feels like you gave something.