1. It is better to remain silent and be thought a fool then open your mouth and remove all doubt. If you are not sure of something, it’s okay to say that. It is always good to ask questions to help you understand something better.
2. People really like to be complimented and praised. But people hate to be criticized maybe 20 times more than that. If you criticize a person, even correctly, they will often hate you forever. Sometimes when you and your own business or you are in a partnership of some sort it is necessary, but be very careful and be aware that too much criticism destroys relationships.
3. Avoid talking about people behind their back. Especially avoid saying anything negative about them behind their back. Such statements always get back to them and then they will really hate you forever because they feel like you are backstabbing them.