One of the core components in the Montessori Philosophy is independence. Independence needs to be taught just like tying shoes. The child should be able to do as much for themselves as they are capable of. If you want a child to do something you need to teach them, you need to be consistent and you need to start at an early age. With a very young child, this would include feeding him/herself. A young child can slowly learn to use a spoon and try and get that food from the bowl to the mouth. It will be messy. If you are not fond of messes, I do understand. Dress your child and yourself in clothes that you are not attached to. Put a bib on the child and a splat mat on the floor. You can not spoon feed your child for the rest of his/her life.......they will learn.
Year after year without fail I would have a parent show up at my classroom door and see their child clean up their work without complaining or throwing a tantrum. The jaw of the parent would be on the floor and then he/she would ask "How did you get him/her to clean up, he/she won't do it at home?" Here's my answer- The child knows my expectations from day one. As soon as the school year starts I tell each child, "When you are done with something it goes right back where you got it from." That's it, end of story. If you do not put away your work when it is completed you may not take out anything else. The rule doesn't change. If you put your work away, you may go to the playground, you may go to the easel etc. This rule can be applied at home also. If you want to go outside you need to clean up inside first. The child will then clean up and go out. If the child does not clean up, there is no outside time. Again, that's it, end of story. If you ask the child (at home or at school)to do something and they do not listen there needs to be natural, concrete, timely consequences.
This is why I love Montessori. I started talking about independence, which led to care of self,which led to natural consequences and so on. Everything in Montessori and in life I think is interrelated............one thing leads to another which leads to another.