<Source: Revised from Anglican Church Singapore Mental Rehabilitation Centre Courses.>
Below are my own Cstan98 study notes. Not mean to replace actual course.
This Social Skill - Assertive = 50% Confident + 50% Humble.
If You expect to fight 1 10-dan enemy in one month time. By right. You should train Yourself to at least 10-dan by then right? Or else. How to stalemate?
If You need to back one step. Ask your enemy to back one step also. Always stalemate.
The me Cstan98: "You are sissy armed forces (SAF). Don't worry. The me is also pussy armed forces (PAF)."
OCBC (Overseas Chinese Banking Corporation): "(when enemy bank sabotagers make untrue rude online). Madam/Sir. Can You tell Us more about it. (Quiet... Because everythings are recorded in online internet.)"
The me Cstan98 to Wife Choy: "why is there always a Hamster in the house. Who always keep so much things (rubbish treasures) in the bedroom?"
Just stalemate. You need not lose. Also not win.
Your tone of voice should sound confident. Not too harsh.
To be assertive. You need to define your boundary: "me is very upset with what you do. Please don't do it again." Assertiveness means you assert your rights to get somethings done.
Get effects You want.