"No" is an interesting word.
There are many perfect ways to say it. There are many cruel and unnecessary ways to say it.
Cultivate saying "no".
"No", "no", "no". Learn beautiful ways to say "no". Learn sexy ways to say "no". Learn ways to say "no" to children or childlike people. Learn aggressive ways to say "no". Learn passive ways to say "no". Learn professional ways to say "no". Learn how to laugh with good cheer while saying "no". Learn how to say "no" in such a way that "yes" might be possible later. Learn how to say "no" and mean it forevermore. Learn how to say "no" to a friend, to an enemy, and to a member of your family. Learn how to say "no" while touching someone you love. Learn how to say "no" to a person at a service station pumping gas into your car and trying to sell you wiper blades and a new fanbelt. Learn five silent ways to say "no". Then learn two more you didn't think of before. Learn to say "no" at a busy, stressful intersection. Learn to say "no" in a field of grass with nothing between you and the sky. Learn how to say "no" in the morning while sipping a tasty cup of coffee. Learn how to say "no" in the evening, as you're going to sleep. Learn how to say "no" in an Austrian accent. Learn how to say "no" in English, French, Spanish, and German. Learn how to say "no" in Vietnamese.
Now, replace all the "no"s with "yes"s (and vice versa) and learn those ways, too. Do these things and you will have opened a new book on communicating with human beings.