Highlight another person's strengths when you can.
The Pygmalion effect is known to show that expectations of others make them become a self-fulfilling prophecy. For example, saying someone is really good at math when they’re actually average will make them become a better math student. Why? Simply due to the expectation you placed on them, they want to prove you’re right about them. Also, by highlighting others’ strengths in conversations with others, the positive attributes you prescribe to them rub off on you!