I'll start
Never let a toddler drink out a shoe
Never leave face paints unsupervised on a inadequately high surface
If breastfeeding, always return you boob to it's rightful place before answering the door
Do not relent when people say your child will like Knex, it is Satans plaything.
Never let your teen read child rearing books on raising teens, they will use them against you for purposes of evil.