I like to follow the motto - start as you want to end. So if you want the end result to be a child who doesn't require being held all day long then don't start it, even though he is new and transitioning.

I think we need to give kids more credit than we do. They adapt quickly if you are consistent and learn what is expected. We are usually dealing with children over 12 months of age and they have the ability for the most part to catch on to things. Each child is different and some need more affection and attention to transition but this child has been with you for over 3 months so it is time to let him scream and self soothe.