A few things I've learned the last few years:
#1 Always remember the purpose of parenting: To help your children navigate this life. Your job is to help them grow into healthy, productive adults in this world. Don't just try to make them mini versions of you, or anyone else for that matter. Help shape and mold them based on the clay you were given. Each child is unique in their thoughts and natural personality. Hone and shape who they are to begin with by helping them overcome habits that may normally be turned toward selfish/damaging pursuits.
#2 Always parent in love: Never discipline in anger. Always have your children's best interests at heart. Whether you are reading with or discipling your daughter, you should always be acting in love. Remembering rule #1, you will not help your child in anything but being bullies if you are selfishly acting out in annoyance or anger when your child misbehaves. It may be easier to love your son when he's smiling and playing joyfully, but you are nevertheless called to act in love when he's acting like the immature child he is. Something that I believe goes along with parenting in love is the importance of having strong convictions about your parenting style and decisions. You should know why you've placed the boundaries you have for your children. Is a certain rule in place in order to teach your child a certain desirable trait or does it just make your life easier. You should also know which of these rules are standard rules of humanity and which of them are "house" rules. Help your children know the difference as well. Also remember that kids will be kids and you should never discipline for childishness (which is not the same thing as disobedience). Accidents happen and shouldn't be punished. An accidentally broken plate or spilled glass of milk is not a matter for punishment. It's a moment to love you son let him know that he's more important than a mess on the floor.