Never rescue your kids from mistakes. If you do, they will just continue the same and never learn to improve. So in effect, parents are spoiling their kids by allowing them to commit the mistakes repeatedly. Instead have a protective eye, ensure their safety, warn them on the consequences, still if they are continuing with their mistakes, let them do it. They will learn naturally from their consequences. And why not build up some harmless consequences, if they are not learning naturally..;)
And on the other side, if you are not enforcing those rules and disciplinary actions, kids will feel really bad, like you are not bothered on them.. So never hesitate to have disciplinary actions. So switch the mode very often.