Although your youngest infants cannot complete Montessori works or develop much independence, there are many ways you can incorporate a Montessori lifestyle in your care of infants. Montessori is not just a form of education -- it's a way of life. If you want your home to be truly Montessori, start at the beginning!
Young infants have no independence or control over their own actions. They are constantly being picked up and put down, often with no warning of the change to come. One of the ways you can begin to prepare your infant for developing independence with her body is to talk to her about what you are doing. When you are going to pick her up, say, "I'm going to pick you up now!" Even the youngest infant can begin to understand that there is about to be a change, but the warning helps them to feel safe. When your infant is a little older, she can lift her arms up to you when you say you are about to pick her up, beginning to take an active part in the process. One of the things I learned in my Montessori training that really stuck with me is that you never approach a young child from behind and pick them up when they can't see you. Imagine how scary that would be if it were to happen to you as an adult! It is no less jarring for a young infant, so show them the same respect you would expect for yourself -- move to where they can see you approaching, and use your words to tell them what is about to happen.
Telling a young infant what you are about to do also lays an important foundation in language development, as you are exposing your child to new words along with the concrete representation of what they mean. When you are changing your child's diaper, rather than giving her a toy to occupy herself with, talk to her about the process of diaper changing. Tell her exactly what you are doing. Name her body parts as you are dressing her. This involves her in the care process, leading to greater interest in self-care when she has the motor skills that are necessary to take part.