My LO just turned 3 months and I usually have to rock her to sleep at night.For naps I have to hold her the whole time if I want her to sleep. I dont understand "sleep training" though. Is this different from CIO? My husband laid her down and she cried for 20 min but then fell asleep so is that better than holding/rocking her everytime? I feel like I am setting up bad habits. Any advice on "sleep training" would be great. Thank you!!