This question is frequently asked to me by new parents.
My answer is always - you should never "discipline" an infant!
An infant is incapable of comprehending an "offense" or associating it with the "discipline". Prolonged bouts of crying can cause considerable frustration for parents and too many have proceeded to striking or shaking their baby causing irreparable brain damage that results in life long disabilities or even death. NEVER SHAKE OR STRIKE A BABY!
Infants need to be held, cuddled and calmed by a loving parent, not "punished" for acting like a baby.
Dr. James Dobson (a noted psychologist) says babies need "loving leadership". He says parents need to have the courage to do what is right for their babies, even if the child protests vigorously . Dr. William Stonecker, (an American pediatrician) stresses the importance of parents taking charge right from day one. Too often he says he has seen moms who are afraid of their infants. They would call his office and frantically say "My 6 month old baby is crying and seems very hot." The doctor would ask what the child's temperature is to which the mom would reply, "I don't know. He won't let me take it." This mom has already yielded her authority to her infant and she may never gain it back.
Good parenting and loving leadership go hand in hand. It should begin on "day one" and continue throughout childhood and the teen years.
Rick Harper