1. Find something positive to say, "That was very interesting. I never thought about it like that before…"
2. Let people know when you agree with their point and why, "So do I…", "Yes, that's true…"
3. If you disagree with something, instead of rejecting the other person's ideas, explore them, "What makes you think that…?" Have you thought about…?"
4. Be constructive and specific. If you don't agree, explain why and give evidence or examples rather than just saying no.