2 simple easy ways on how to say 'no' yet people do not get angry

I discovered several ways that simple yet works .

1>make it clear up front ;many would simply scare or worry to say no up front because we worry people would get agree. Saying 'no" up front would minimize the changes of other getting angry.

2>set conditions or hurdles- set certain conditions and let other party to agree on before you say yes to them. "if you agree on this, i would do that" way of getting other to co operate with you. you agree to say 'yes' provided other party agree on your request in return.They would not angry as they feel that you are trying to offer help.