[M]Teach them tawheed, prayer at age 7, discipline gently at 10.
[1]Teach the Qur'an, Islamic manners, and good character.
[1]Make du'a for their righteousness.
[2]Teach them life skills.
[2]Allow them to choose their spouse at maturity.
(extra):
[1]Play with your children, hug them, kiss them — the Prophet kissed his grandchildren. (Bukhari 5997)
[3]Touch their head gently and make du'a for them.