Mom, Dad, think before you act!
It is easier to stop difficult behaviour before it becomes entrenched. You should be very skeptical of the phrase “I’m just going to do this once” when it pops into your head in moments of parenting stress. Frankly, whatever you’re thinking of doing, you’re unlikely to do it only once. So unless you’re prepared to spend hundreds of hours in a car with your baby, don’t use a car ride to put your baby to sleep. Similarly, putting your toddler to sleep by crawling into bed with him/her is setting yourself up for a lot of nights of human teddy bear duty.