Let's take this for example, it is bright time Sunday and you got nothing to do. Suddenly an idea of picnic came into your mind and you are sure ready to invite your friends to join your play. You called your friend... "Hey, I'm bored... wanna do picnic?"
In this point of time, you are not insisting your idea whereby if your friend would have then suggested something more interesting, you would gladly amend your plan. (You find this sort of invitation Easy!)
However if you were to insist on your plan when your friends do not show supports, you become unhappy but at least you have successfully made an invitation although the result doesn't pleased you.
Even that you have set a target for yourselves like "I must convince him/her to buy my idea!". You are not suppose to feel difficult.
The main reason making you feel difficult or stressed is that you are afraid of the consequences because you are plotting something, and you are afraid of being exposed then being rejected.
Hence if you are trying to trick someone to buy your idea, the most important thing is do not cheat on him/her but just tell the truth by hiding the sensitive points that might leads to rejection.
