4-6 months is the ideal age to attempt milk baths of any time. Just a few tips for doing milk baths: 1. The water needs to be warm! I leave the milk out overnight and will add warm water until it is a pleasant temperature. And I do so right before the session starts so it doesn't cool down. If the baby generally screams with any bath time, that they will not like milk baths either. 2. We will give them something to distract them from the "uniqueness" of being put in a milk bath... like eating an orange slice. 3. I laid a white round table cloth over a kiddie pool set on my kitchen table, that was lined with a small tarp, then we filled a few gallons of milk and warm water and fruit slices. This way I was able to be next to the windows for some of the shots I wanted to get.