Those first weeks of parenthood can seem like something from The Twilight Zone, when there's no day or night, just endless streams of feeding, burping and sleeping. New parents start feeling like zombies, scrabbling for just an hour or two of sleep.

Some say that with time, babies learn how to sleep more regularly. The truth is, everyone's different. Some fall asleep and don't wake until morning, while others want to feed every hour, on the hour. This is where sleep training comes in. As long as your baby is older than six weeks and over ten pounds, teaching your baby to sleep can be a life-saver. Here are some of the most common methods.

The Ferber Method. Undoubtedly the most controversial of all sleep training methods, the Ferber Method is sometimes known as "crying it out." It works like this: your baby cries in her crib, wait a set amount of time before going in and offering comfort, but never pick her up or offer soothing items like a toy. Then exit the room. If she continues to cry, wait a longer interval to go in, and so on. This method is never recommended for any child younger than four months and is more appropriate over the age of six months, since younger babies need to be fed, changed and comforted throughout the night. Some experts have criticized Ferberizing babies as unnatural and counterintuitive, but others swear by the method. Parenting expert and physician Dr. Mary Ann Block, suggests that "If parents are using training that has them leave the room while the baby is crying, it would be good to have a video camera running so the parent can see the child from another room to be sure that the child is ok and not hurt."

No Cry Solution. Dr. William Sears advocates this less extreme sleep training method, which involves letting your baby's natural cues and habits to lead the way in creating a healthy sleep schedule. He suggests rocking and soothing your baby to point of drowsiness before putting her to bed, and sleep expert Tracy Hogg recommends also picking up your baby and soothing her as often as is necessary. The training portion of the method relies on sticking to a consistent schedule so your baby's brain and body knowns when it's bedtime.

Co-Sleeping. If the idea of training your baby to sleep makes you upset, you might be more suited to attachment parenting. Instead of training a baby to sleep, attachment parents facilitate a natural dependence between baby and parent, often accomplished via cosleeping. However, the American Academy of Pediatrics advises against allowing your baby to sleep in your bed, suggesting attaching a bed to your own instead. For cosleepers, a baby's cries in the night are answered via instant comfort and feeding, with the idea that a baby will cry less in the night if she knows that her parents are near.

Which is Right for Me?

If you think that some type of sleep training would work with your older baby, make sure you do your research. Since all babies are different, you can modify any method to suit your baby's needs, and ask your pediatrician to make sure there aren't any underlying problems that are stopping your baby from sleeping, such as acid reflux.

"There must be consistency in the training," says Dr. Block. "Babies are smart and if the parent gives in once, the child will keep trying. If the consistency is not there, it will be like starting from scratch each time."