What methods should I use with them?
Praise be to Allaah.
We advise you to teach them the Qur’aan and the saheeh (authentic) Sunnah, and the good manners of Islam, such as honouring one’s parents, upholding ties of kinship, honesty, trustworthiness, etc. Make sure that they regularly pray in jamaa’ah (congregation). Also teach them the Islamic etiquette of eating, drinking, speaking, etc. If they grow up with these good manners, they will be guided and will remain steadfast, by the permission of Allaah, and they will grow up in a good way that will benefit them and their ummah (community), and you will have a great reward.