1. When a group of people laugh, each member of the group will instinctively look at the person they feel closest to.
  2. While negotiating with someone leave your hands and palms visible, this is the sign of trustworthiness.
  3. Nodding your head while talking or asking a question will make the other person more inclined to agree with you.
  4. While telling a lie adding an embarrassing detail can make it more believable.
  5. If you ask someone a question and they only partially answer just wait and stay silent, they will usually continue talking.
  6. People remember unfinished things better. If a song stuck in your head than think about the last few lines and you will forget it faster. This is called Zeigarnik Effect.
  7. Getting someone to do a favor for you makes them like you more.
  8. Chewing gum can relieve stress. Chew one during an exam or while doing something stressful.
  9. Keep an eye on people’s feet. When talking with someone you can figure out if they are interested in the conversation by looking at their feet. If it is aimed at you they are listening, but if it is aiming elsewhere they rather want to leave the conversation.
  10. If you meet someone for the first time and you have hard time by remembering names just say it multiple times. For example in the first conversation say things like “Hello {name}”, “Nice to meet you {name}” or “Where are you from {name}”. Say it at least 3 times in the first minutes of the conversation and you wont forget it.
  11. If you meet someone show excitement, this way the other person will be excited about the meeting too.
  12. Smile and keep eye contact. While in conversation smile at the other person and keep eye contact more than 60% of the time.

Source and more tips