As you might suspect, this method can be very difficult, depending on temperament, and can take many days or weeks. It can be difficult to avoid engaging with your child (and “watching them cry” is very difficult), and it will likely be a little confusing to the child (particularly younger ones) when you don’t. However, with time and consistency, this can be a good option for parents who do not want to leave their child alone to cry but who haven’t had success with other methods, either.
Also on the far end of the cry it out spectrum is the Baby Wise approach by pediatrician Robert Bucknam and co-author Gary Ezzo. In their book On Becoming Baby Wise, they advise against feeding babies on demand around the clock and instead advocate a parent-led feeding, wake, and sleep schedule. Their method involves following a strict nap and sleep schedule and putting your baby down awake so she can learn to soothe herself to sleep. This means there will be some crying, especially at first, as your baby adjusts to your schedule.
Most experts recommend starting when your baby is between 4 and 6 months old. By about 4 months, babies have typically started to develop a regular sleep-wake cycle and dropped most of their night feedings. These are signs they may be ready to start sleep training. Many babies this age are also developmentally able to sleep for long stretches at night.
Pantley offers a gentle and gradual approach to all aspects of sleep, customized to your baby's needs. She recommends rocking and feeding your baby to the point of drowsiness before putting him down – and responding immediately if he cries. Parents are urged to keep sleep logs, nap logs, and night-waking logs. Pantley also describes a six-phase process for teaching a child to sleep in a crib.

Typically, formula-fed infants who are growing well no longer need to feed at night by 6 months. Breastfed infants may continue a little bit longer, but typically no longer feed at night by 9 months. If your baby has been falling asleep independently at bedtime for a month but still waking to feed, you may want to consider weaning at night. Be aware that if you are breastfeeding, this may lead to a reduction in milk supply.
It’s okay if you’re not ready. You aren’t missing out on sleep training if you skip it at 4 months: You truly can start sleep training at any age, even in the toddler years, although experts say it’s smart to be aware of developmental milestones and adjust baby’s sleep schedule accordingly. For example, the week baby learns to walk may be tough to implement a sleep-training schedule, and even a sleep-trained baby may see a regression simply because he’s going through such a developmental shift.
After going through your bedtime routine, put your baby in their crib, leave the room and wait a specific amount of time (say, a minute). Then go in and reassure your baby with words like “Mommy loves you” or some kind of touch, such as a rub or pat. McGinn says it’s preferable not to pick the baby up. Garden, on the other hand, reserves this method for babies seven months and older. (In her opinion, younger babies require a parental presence so they know they haven’t been abandoned, especially if they’ve worked themselves up into a frenzy.)
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