Children need consistent child-rearing practices. Overindulgence or too much leniency by either parent can make it more difficult for the other parent to get the child to behave. Constant competition for a child's love through special privileges or gifts leads to a spoiled child. The general ground rules regarding discipline should be set by the custodial parent. Don't argue with your ex-spouse about your child in the child's presence.
Children are quite upset by seeing their parents fight.
Most important, avoid any arguments regarding visiting, custody, or child support in your child's presence. Try to avoid custody disputes. Your child badly needs a sense of stability. Challenge custody only if the custodial parent is causing obvious harm or repeated distress to your child. False accusations of physical or sexual abuse cause great emotional anguish for the child.