The art of saying "NO"

Brain Tracy in his book "Eat that frog" talks about Time Management.He also talks about the art of saying "NO' which needs to be mastered. His words on the same is as follows:

"One of the most powerful of all words in time management is the word no! Say it politely. Say it clearly so that there are no misunderstandings. Say it regularly as a normal part of your time management vocabulary.

Say no to anything that is not a high-value use of your time and your life. Say no graciously but firmly to avoid disagreeing to something against your will. Say it early and say it often. Remember that you have no spare time. As we say, "Your dance card is full."

For you to do something new, you must complete or stop doing something old. Getting in requires getting out. Picking up means putting down. Creative procrastination is the act of thoughtfully and deliberately deciding upon the exact things you are not going to do right now, if ever."