I've been reading several very different educators with several very different theories of education lately: Classical, Montessori, Charlotte Mason, Unschooling.
But some themes are emerging in common with several or all of them.
Respect the child as a human being, capable of freedom with responsibility. Children treated as a doll to be controlled, as a pet to be served and bribed, or as a wild beast to be caged, tend, eventually, to respond in kind. (Children treated as angels, on the other hand, tend to show just how fallen of angels they are.) Children treated as human beings--taught how to care for themselves, expected to help serve others, given responsibility and allowed to deal with the consequences--quickly learn how to be fully human.
Children need meaningful tasks from the beginning. Children need to do things that genuinely matter, not tasks we make up to keep them busy. Real work is what builds the right kind of confidence and keeps the child engaged in his learning. The Montessori book, especially, had some great ideas about how to do this even with very young toddlers, which I may blog more about as I try to prepare things for D1's next stage of life.
Children need faith that the universe is a logical place and the chance to understand its logic. This starts in infancy, with giving them toys that operate in simple ways that the child can begin to understand, instead of reacting arbitrarily. (That does in most of the "brain development" toys out there.) It continues in school by being careful not to give explanations that do not, in fact, make sense, which is sometimes hard for adults to realize because we have so long adjusted to the school way of explaining things.
Don't get between the child and the learning. One of the most common ways this happens is with too much praise or criticism. A child worried about getting the answer the teacher wants is learning little or nothing about the subject at hand--whether that concern has been created by the birch rod of old or the constant positive reinforcement of today.
Not that all praise or criticism is bad. D1 really isn't capable of understanding why she mustn't touch the books under the coffee table, so there I have to use her desire to please me as a motivator. But she doesn't need me interfering with "No, don't put your hand there," "Yes, that will work," as she puzzles out the right handholds to pull herself up. She can figure that out for herself--with a few falls, but the last thing I want to do is make her afraid of falling.
When she is done concentrating on the task at hand and looks over with the triumphant grin of one who has accomplished a great thing, then I can smile with her and enjoy the moment. But she didn't pull herself up for my sake--she did it for her own.
Another way we get between children and learning is with too much explanation or analysis. More often they need to be given the chance to puzzle it out for themselves, or to figure out what they think of the poem, not hear our blather on it.
Don't assume that the right answer equals learning. Many clever students make a very succesful strategy of figuring out how to game the system without bothering to actually learn anything. DOB and I were discussing one author's theory that formal math (worksheets and such) should wait until age 10 and both admitted that we went through years of handing in well-filled out math sheets without really understanding what was going on. I didn't understand most of elementary math until I was a teenager and was teaching it to my younger brother, and I was an excellent math student who loved the subject.
The best insights come from observing your own. No matter what the book says, you can't figure out what effect something is having on a child without watching them. For a classroom teacher or daycare worker, this is simply impossible. They have too many kids to watch at once. Parents have more opportunity and motivation, but I'm afraid too few of them give themselves the time anymore. It's often so much easier just to accept gratefully whatever will quiet the baby down, keep the toddler busy, and help the grade schoolers' schoolwork, without giving any consideration to what kind of person it is helping to make them.