While we may look for advice in the form of directives, concerning what to "do" to "produce" good children, that old adage, "The apple never falls far from the tree." seems to be persistently true.
Children are pure human beings, uncomplicated by those things that make adults less genuine and lucid. They are like mirrors and their conduct may tell us a great deal more about ourselves as adults than we may be comfortable with.
A man may go to great lengths to assume the appearance of one who lives in comfort, but if he is poor you will know from his children. A woman may assume the manner of a gracious hostess but if she is in fact troubled it will be reflected in her child- in simple, uncomplicated ways. I've come to appreciate that this reflective-ness of the child is very much connected to the way the child learns and to the veracity of that old adage.
The simple fact is that there is very little a parent can purposely say to a child that will make them better human beings than their parents. Sometimes parents are puzzled by children's ability to detect hypocrisy or injustice even though they may be quite easily duped by what adults would recognize as obvious lies.
That ability on the part of the child might be connected to the fact that young children learn mostly by imitation and interaction and less to by verbal instruction. That may be why when a parent is being hypocritical the child senses it immediately whereas the parent may say something hypocritical or even untrue and it may well evade the child altogether. What this means is that how a parent is has a far, far more profound effect on a child than what the parent says.
So a parent who is concerned with cultivating good character for themselves in private and public is much more likely to raise children of good character. For we are seldom aware when our children are absorbing our states from our natural actions, words, and reactions in the home. Children first internalize our unguarded natures evident in, for example, comments we may make assuming, mistakenly, they are in another room. They see what disgusts us and what we laugh at. They note our priorities from our decisions and reactions more than our words.
They look at our expressions when we talk about white people, or black people, or rich people, or poor people and they learn. Then when a little one does or says some objectionable thing, that we scarcely realize was merely copied from our own ways, we launch grand sanctimonious lectures (perhaps to be triumphantly recounted later to friends).
Yet the child will sense, based on our daily conduct, when there is a disconnect between our sayings and doings while we are left wondering what it was that so soundly convinced them to the contrary of our high-minded exhortations.
One could therefore say that arguably the most important rule of "parenting" has nothing at all to do with the child. And that rule is what was mentioned by Imam Abi Abdillah Al-Muhasibi (Allah shower him in mercy) when he said:
"Know, may God grant you mercy, that genuineness (sidq) and sincerity (ikhlas) are the basis of every (sound) condition."