"By the time your baby is 3 months old and has developed a fairly predictable 24-hour pattern, it becomes more important for you to provide increasingly consistent structure. If you do your best to establish a reasonable and consistent daily routine and keep to it as much as possible, then it is likely that your child will continue to develop good patterns. If instead you allow the times of your child's feedings, playtimes, baths, and other activities to change constantly, chances are his sleep will become irregular as well."
Do your research, talk to your doctor and if you’re overwhelmed, consider hiring a sleep consultant or taking a workshop. Your baby’s sleep might seem like a mystery to you, but there are people who understand the complexities and can help. While not everyone agrees with every approach, no one would argue with the benefits of a good night’s sleep, for babies and exhausted parents alike.
There’s also no need to institute a regimented cry-it-out plan if what you’re currently doing is working for your family. But good sleep habits never hurt, and being able to fall asleep on one’s own is a necessary life skill. If you sleep-train at a time that’s developmentally appropriate for your baby and with the basic ingredients of healthy sleep in place, you can minimize the amount of crying your baby (and, let’s face it, you) will do.