Imagine living in a lawless community, imagine the chaos and destruction that comes with. Now in your imagination, what do you think would have prevented the chaos and destruction?
Yes you guessed right, rules, regulations, and every other thing that puts one in check. If this can solve the chaos in a community, how effective do you think it will be within a family, especially for children? Children are prone to misbehave. Every once in a while they feel the need to explore and test the authority, but while it is expected, it should also be anticipated with;

Established rules: Having a rule against all misconduct is a way to go when trying to instill discipline into your children. Because just as stated above, a lawless community is a sinless community. But when you have laid down principles, it helps to bring out the discipline in children. Although establishing rules might not be enough to stop the children from misbehaving, it helps reduce the chances. Moreover, it is important to note that establishing tiles will just not be enough because the children will definitely break some of it, that is why it is also important to implement a punishment when they do not obey. For example, if you tell them not to play games at late hours, say 10 pm and you catch them playing, while their plea might be enticing to forgive, the best thing to do at that point is to make them serve the punishment for breaking the rules. This will not only teach them discipline but also the responsibility to bear the consequences of their actions.
In terms of discipline, be their role model.

Children emulate their parents a lot, so while you are preaching the gospel to them, it is best to also act on the gospel (practice what you preach). The act of discipline is a trait that is learned over time, and no matter how much you want your children to be disciplined, if you are not, they are just going to be a chip off the old block, the good thing is that the same thing applies if you are.