Put a big wall clock in children's room, this is good according to Feng Shui and also instills a sense of time and discipline in children.
Put a one foot high mirrow away from children's bed which instills confidence in him. Make sure that while sleeping your child does not see his reflection in this mirrow.
Try not to allow children to sleep on mattresses on the floor. Yes, this allows young children not to fall off beds but it also causes young children to fall sick frequently. The reason is: chi is not able to flow underneath the bed. Ideally, chi should circulate around the mattress where our children sleep to allow them to be healthy.
For young children, try to have their back to the wall when they write. It is important there should be a solid wall behind a children's writing table. This allows the child to have support so that he can sit there and study longer rather than for only half an hour and then they tend to move about because there is no solid wall behind their back. Adjust your writing table.
Do not allow children to sleep on double bunk beds even if it means saving space. The child sleeping underneath will not have "fresh chi" and so his health might be weak. But if due to space constraints, then monitor your child's health if not add in a metal 6 rods wind chime or a crystal sphere, to break up the "stale chi" around his bed.
If your child usually falls sick in that bedroom: Then either change them to another bedroom or simply hang a six rod metal wind chime as the metal element will break all the earth energies in that room. After hanging, if the wind could not do the job for you then you will have to "chime" it yourself and then watch for the good results.