A famous saying about interpersonal communication:

Don't do to others what you don't want others to do to you. -Confucius "The Analects of Confucius"

A gentleman's friendship is as light as water, and a villain's friendship is as sweet as Li. -Zhuangzi's Zhuangzi Samwood

A leisurely manner is more heartbreaking than an aggressive attitude. -San Mao?

Don't say whatever you want. Everything must be done in threes and fours. Be kind to people, but don't be too intimate. -Shakespeare

You may forget the person you laughed with; But you will never forget the people you cried with. -Ji Bolun

If we want to make friends, we must first do something for others-things that need time, energy, consideration and dedication. -Carnegie

If you want to open people's hearts, you must first open your own. If you want to accommodate people's hearts in your heart, you must first put your heart into others' hearts. -Qian Hammer Book