For some people, saying "no" can be very difficult. Reluctance to offend someone or something like that makes me agree when I want to refuse. It's absolutely wrong with yourself. Of course, a person should not be an absolute egoist, but still thinking about yourself and loving yourself is incredibly important. Therefore, you need to know how to say "no" and do it when you really want to say "no", putting your needs and desires above strangers, if this can be done without a twinge of conscience.
How to learn to refuse and say "no"?
It is important to understand that failure is normal. Far not always there is an opportunity to be engaged in performance of another's requests, after all each person has a life and the affairs which stand on the first place. So do not be shy to say "no", thinking that in this way you can offend a person. This is the first step to learning how to deny people.
Further it is necessary to understand, how it is necessary to refuse. Of course, if you just bluntly say "no", then a person can really be offended. But if the refusal is elegant and polite, then there is no question of any offense. At least for your part you can be calm. One of the most common forms of polite refusal: "I would love to, but ..." It is important not to go into too spatial explanations of why you can not fulfill the request. You can simply refer to employment and pressing matters. Also, as an option, this form of refusal can also be used. "It's a great pity, but I do not particularly understand this, so I can not help." If you are offered a case that is simply not in your competence, then do not be afraid to say this.
In general, the most important thing in how to learn to deny people their requests is to understand that rejection is not an insult and not rudeness, and sometimes a necessity. Each person for his life hears a lot of failures and this is absolutely normal.