My son will be a year and a half when our baby is born but I wasn't planning on doing anything because he just seems too young to understand things like a gift from a baby.
I say do it with a gift. I still remember the jack in the box my sister brought me when she was born. I was 2. I was a little confused how she brought it with her but I took it as a sign of friendship.
Our son will be 2 when the baby is born. He's not going to fully grasp the concept of having a little brother at that age. We're starting to talk about it with him now so that it might not be as much of a culture shock (it will be anyway). For example, we'll hang out in the (work in progress) nursery and show him the crib and say "this is where your little brother will sleep". Just little things like that every once in a while to reinforce the idea that a baby will be coming to live with us.
I think this qualifies as a social, rather than a business situation. You should always be sure to introduce the younger child to the older one first. Use their preferred titles. Also, I think it might be a good idea to start a conversation with something they have in common - drooling, pooping, came from same uterus, etc.
Re: introducing my 1.5yr old son to his newborn brother
I mean come on, what?