From early childhood, the child must learn the basic rules of hygiene: the neck and face should be washed at least twice a day (morning and evening). Be sure to wash your hands before eating and do not forget about it, coming home after a walk. Teach your child to brush his teeth, buying him a baby brush (just like adults) and "delicious" toothpaste. Let him from an early age will get used to brush your teeth in the morning and evening.
Will instruct the child not eating unwashed vegetables and fruits, greens, and you will be spared a lot of trouble in the future, when the child will become more independent.