This is one that my husband and I really really agree on. You have to have some type of plan. With our first child, we chose to be the only people who would feed him or change his diaper for the first 3 to 6 months. With our second child, beginning nearly 3, we had to come up with some other attachment plan. We again set out a length of time and committed to being her only caregivers for the first 6 months. We take turns staying/working from home to full time parent her for the first year. We were the only ones to give her meals, snacks, snuggles and all her other needs. This is our attachment style. I think it is incredibly important to remember to give yourself breaks and that you won't necessarily be the only person to give them a cup of milk, when you are introducing them to your extended family at Christmas, but you have to have some type of plan to show them that you are their parents, you belong to them, and can be trusted.
This also means figuring out how and when you will be introducing them to new people (their new family). Always error on the side of caution. Let your people know that you will be taking time to bond as a family. There is no set timeline, but listen and observe your new child and take things at their pace.