1. Full Extinction, aka, cry it out.
You put your baby in the crib while she is still awake, ideally unswaddled and without a pacifier, and you leave her to discover how to self soothe, translation: calm down on her own until she falls asleep. When she wakes during the night, you don’t go in and instead let her put herself back to sleep.
Some pediatricians say you should start at 14 pounds, 4 months; it’s ok, some say, to wait until 6 months. This method is best done when a baby is younger, preferably not able to stand in the crib. It is also best done when a baby is learning cause and effect (from 4 to 7 months). This method tends to get pretty tough to implement after 7 to 8 months.
2. Time Checks, a.k.a., Ferber or Ferberize.
In this method, you put your baby in the crib awake and leave him to self-soothe. You go in at timed intervals to check on him, calm him down, through touch and/or your voice, and then leave again. You can follow Ferber’s suggestions in his book or make your own plan. I suggest 5 minutes, 7 minutes, 7 minutes, and then every 10 minutes. You do the same thing during night wake-ups. This is a great choice for any age (child needs to be in a crib or with a gate across the door).
3. Gradual Extinction or Fading.
You spend three nights very close to your baby while she falls asleep independently, you can touch her, rub her belly, shush until she goes to sleep. Then, the next three nights, you shift closer to the door and just use your voice, and then you spend the following three nights either just outside the door or in the doorway where your baby can hear you. You then graduate to timed check-ins from the door beginning around day 10 of sleep training'
You follow the same plan during night wake-ups and eventually for naps. This is great for any age, especially for toddlers who sleep in beds.
4. Gentle methods
Elizabeth Pantley’s No Cry Sleep Solution Method includes a lot of picking your baby up and then putting her down until she goes to sleep; or Harvey Karp’s Awake to Sleep Method, where you have your baby fall asleep in your arms, and then gently wake him up as he goes into the crib. These methods are best for young babies, 4- to 7-month-olds.