Here is a helpful answer from C.J. Mahaney to a dad’s question about helping his son not be so addicted to video games.
It is too easy for me to view my son’s form of idolatry as childish, but in essence, at root, there is no difference between our idolatries. His expression is consistent with a 12 year old, mine is consistent with a 56 year old, but in essence it’s no different. Therefore I must make sure my heart is softened by my own sinful tendencies. I don’t want the study to be punitive, I don’t want it to be (if possible) connected or related to discipline, because I think that can make it more difficult for a child to comprehend and to be convinced I have their best interest at heart. I want to supplement it with my own stories.
At 12 years old I would want to start leaving your son with questions to consider rather than pronouncements. But from 12 years old on up, it is far more complicated than when they are younger. For a toddler, discipline is pretty simple. You are not having to work through heart issues. It is a blatantly ethical world, at that age, nothing but right/wrong, yes/no. But as they get older you want to draw your child in and give him an opportunity to think about his own heart, think about it in relation to material, think about it in relation to Scripture, think about it with time for the Spirit to possibly convict. You are not bringing every conversation to a conclusion that he must agree with.
Read the whole thing here.