The boy is a trust given to his parents; furthermore, his heart is a pure jewel; it is accepter to whatever is engraved on it. If he has been accustomed to the good, he would apply it in his life and he would have the reward of this shared by his parents and instructor. On the other hand, if he is accustomed to the evil, he would apply it in his life and the punishment of this would be shared by his curator. Therefore, parents should care for the child and educate and refine him. Also, they should teach him the good manners and keep him away from the bad company and do not make him accustomed to luxury or make the reasons of welfare desirable to him, lest his life is wasted in searching for them after growing up.
Rather he should be monitored from the beginning of his life. He should not be nursed except by a righteous religious woman that does not eat except what is permissible, because there is no blessing in the milk which is produced from unlawful earning. Then, when the characteristics of realizations appear on him (shyness is the first of these characteristics), they refer to having intelligence and perfect thinking at the time of attaining puberty; and such kid could be refined well by utilizing his shyness. The characteristic that dominates the child first is greed; therefore, he should be taught the etiquettes of eating and should be accustomed to eating bread alone at sometimes, lest he might be accustomed to eating complete meals and thinking that having complete meals is necessary. Eating much food should be made undesirable to him by declaring that the one who eats a lot resembles the animals. Also, wearing white clothes should be made more desirable to him than the colored and silk clothes, which should be made known to him that they are the clothes of the women and effeminate persons. Furthermore, he should be prevented from mixing with the children who are accustomed to luxury and he should be occupied with learning the Holy Qur`an, Hadith and the biographies of the righteous people, to plant in his heart loving the righteous persons. Also, he should not memorize the poems which mention the forbidden love.
Whenever the child displays good behavior or good act, he should be honored for it and rewarded by something that pleases him and praised before people. On the other hand; if he, in some times, did the contrary of this; he should be tolerated. But if he repeated the same wrong, he should be blamed privately and alarmed by the possibility of being watched by people. In the same time, blame should not be lengthened, because this might make it trivial for him. Furthermore, the parent should care for the solemnity of this talking. Also, the mother should make him fear the father, and he should be prevented from sleeping at the day, because it leads to laziness; and he should not be prevented from sleeping at night; rather he should be prevented from the luxurious beds, to have his body strengthened.
He should be accustomed to the hardness in bed, clothes and food. Also, he should be accustomed to walk, move and sport, lest he might be accustomed to laziness. Moreover, he should be prevented from boast of something his parents have, his food or his clothes; rather he should be accustomed to modesty and generosity. Also, he should be prevented from taking something from a child like him and he should know that taking is lowness while granting is loftiness. Furthermore, loving gold and silver should be made detestable to him, and he should be accustomed to not spitting or blowing his nose in his sitting area or yawning at the presence of others or putting a leg on the other or talking much. Also, he should be accustomed to not talking except if his talking is an answer and to listen well when the others (who are older than him) talk and to stand up for whoever is older than him and to sit down between his hands.
The child should be prevented from the obscene talking or being mixed with those who talk obscene words. In fact, the origin of guarding the children is guarding them from the bad company. Also, it is desirable to allow him, after the time of the school, to have nice play that gets him out the fatigue of the school, because it is said: “Make the hearts rest to understand the remembrance”. Also, he should be learnt obeying and glorifying his parents and teacher. And when he reaches the age of seven, he should be taught prayer and should not be allowed to neglect purification, to be accustomed to that. Furthermore, he should be filled with fear from lie and betrayal. And when he becomes close to the age of attaining puberty, he should be trusted.
You should know that food is medicine meant for having the body strengthened for obeying Allah Almighty. Also, the worldly life is a temporary life its pleasure would end by death which is expected in every hour. Therefore, the prudent person is the one who prepares himself for the Hereafter, and if his upbringing was good, this would be engraved in his heart as the engraving on the stone. Sahl bin Abdullah said: “I was three years old, when I used to get up at night to see the prayer of my maternal uncle, Muhammad ibn Siwar. Then; at some day, my uncle said to me: ‘Would not you mention Allah Who created you?’ Whereupon I said: ‘How could I mention Him?’ He said: “Say Allah is with me, Allah looks at me, Allah watches me; three times in your heart without moving your tongue.’ I said so for nights, then I told him and he said to me ‘Say it eleven times each night’.”
“Then I said it and felt its sweetness in my heart. After a year, my uncle said to me: ‘Care for what I taught you and observe it till you get in the grave.’ So, I continued observing that for years and felt its sweetness in my heart. Then my uncle said to me: ‘O sahl, he who has Allah with him and has Him looks at him and watches him, could he disobey Him? Beware of disobey?’ Then I went to the school where I memorized the Holy Qur`an at the age of six or seven. Then I used to fast the whole days of the year and eat nothing but the bread of barley, then I used to pray all the night.” 
Quoted from Mukhtasar Minhaj Al-Kasidin by Imam bin Qudama Al-Maqdisi
 A group of three men came to the houses of the wives of the Prophet asking how the Prophet worshipped (Allah), and when they were informed about that, they considered their worship insufficient and said, “Where are we from the Prophet as his past and future sins have been forgiven.” Then one of them said, “I will offer the prayer throughout the night forever.” The other said, “I will fast throughout the year and will not break my fast.” The third said, “I will keep away from the women and will not marry forever.” Allah's Apostle came to them and said, “Are you the same people who said so-and-so? By Allah, I am more submissive to Allah and more afraid of Him than you; yet I fast and break my fast, I do sleep and I also marry women. So he who does not follow my tradition in religion, is not from me (not one of my followers).” [Reported by Al-Bukhari]