Warming your hands up before shaking hands
Back in the day, people used to shake hands as a means of checking whether the other person was unarmed. Today, it’s become a tradition in business and nearly every other part of social life. If you want the other person to trust you, make sure your hands are warm.
People associate clammy hands with suspicion and mistrust, and they’ll actively point out that your hands are cold. Before meeting other people, warm your hands up in the bathroom, either by washing your hands with hot water (don’t’ forget to dry them!) or using a hand dryer. They won’t trust you enough to lend you a couple bucks, but they won’t automatically put their walls up when engaging you in conversation.