Routines are soothing--they help you organize your life and let you do more without planning every detail. For an infant, routines provide an important sense of security. Your baby learns from the consistency and predictability of your responses that he matters and that he can make things happen.
Help Your Baby Remember
A routine can serve as a memory aid. Very young babies don't remember much from one day to the next. Every time you change his nappy, sing him the same song, and make the same stuffed animal dance on his tummy--this gives him two extra cues to help him remember the experience from previous times.
If you sing a lullaby to your baby as you rock him to sleep, he may come to associate the song with the feeling of relaxation. The familiarity will remind him: It's time to relax again. He'll know what to expect. This will add to his understanding of how the world works, and he won't feel as much like he's in the middle of chaos.
A Feeling Of Security
Routines add to your baby's feeling of security. He's learning more about you each day; he already knows that you'll come to him when he cries and that you'll take care of his needs. Routines add to his growing sense that he is safe with you. He knows what to expect from you; he can count on things to happen a certain way.
Same Routine, Different Caregiver
Routines also make it easier for your baby to accept care from other providers. If you have a certain way of organizing the day with scheduled times for your baby's feedings, bath, and naps, your baby may adjust to a sitter more easily. He'll have to make the major adjustment of dealing with your absence, but other details of his day will remain in place.
Not everyone wants or is able to organize life to this extent--some babies as wells as some adults require a more flexible approach. Whatever routines you do establish will be comfortable, familiar territory to your baby in the midst of changing situations.