To carry, not having spilt, a glass of water is not as easy as it seems at first glance. Ask the kid this lesson: he must carry for some distance and not to spill the water in any vessel, for example, glass. First pour a half Cup (about two thirds), next time better, etc. more and more complex task: for example, you must first remove the glass in any way, then carry it out at arm's length; straight, to go with turns; in the way to pass the Cup from one hand to another. Next he will tell you what other difficulties you can come up with.
