St. John Bosco spent most of his life caring for children, not only for their physical wellbeing, but most of all for their spiritual health.
He wrote many manuals for children that included short prayers that he wanted children to recite on a daily basis.
One of these prayers, from his Companion of Youth, is very short and simple, asking for the saints' intercession to become a saint.
St. Aloysius Gonzaga has always been regarded as a special patron of children, but in reality, any saint could be placed in the prayer.
They key is the last part, "help me to be a saint."
If a child prayed this every day, God would certainly hear and answer that prayer, giving the child the grace they needed to be a saint and to follow him.