Observational drawing for children is the best way to practice their hand-eye coordination. It forces them to look with intent instead of drawing the "idea of a object" and takes them away from the generic preconceived shapes of flowers, houses, people... It also teaches them how objects/shapes/colors relate to each other, where they are placed in space, the idea of different masses and such. This is not to be done for the sake of accuracy but with the hope that they will become intimate with the act of looking (and deal a bit with the frustration!). What we draw that way enhances the process: we tend to remember it in a deeper way. (picture: observational drawing of blocks).