I have observed over the years the tremendous effort that teachers put into motivating students by crafting creative lessons and class activities. In fact, a teacher's ability to charm, coax, bribe or otherwise convince children to do their work is considered by some to be the mark of professionalism and talent. The problem, of course, is that all of these motivations toward effort are external to learning. Students do their work not so that they may learn, but so that they receive a good mark, or an approving look from a teacher, or so that they might avoid being held in at recess. It is true that the children give effort, but all the while they steadily become more and more dependent upon extrinsic motivation and more and more jaded toward school work.
The key to a highly effective school, I think, is to structure it in such a way that children find joy in learning. That is, to find learning intrinsically motivating. Of course, you cannot do this if you expect children to plow through mountains of worksheets, drills, quizzes and projects. Rather, a school must guide a child to material that holds interest on its own. In this books, real living books written in a literary style, are our secret weapon. Children have an innate appetite for knowledge and a greatly underestimated capacity to enjoy and learn from stories well told. If we feed that appetite with the best material available, it grows and becomes more and more refined.
What we must studiously avoid doing, therefore, are those little things which convince the child that the effort of learning is a drudgery, a contest, or a means to some more desirable reward. Even a child's love for her teacher can be put to bad use. The beloved teacher who tells her students "you should work hard because it will please me" is doing long term harm for short term gain. The child's vanity is fed and grows, while her knowledge and self-reliance are neglected, all for the ephemeral reward of a filled out worksheet or high quiz score.