What is the worst CV mistake EVER? and how to write a successfully CV ?

overloaded information and lying. accurate with basic informatin.

In my opinion, the worst CV mistake is to lie or provide misleading informaion on your CV. Not only can this lead to an integrity issue, but it will also manifest itself in the form of low self-esteem and low-confidence during the interview session. Be honest, even if you don't have the relevant experience, at least you won't be burdened with the fact that you lied on your CV.