If your child is in scouts or some other program like that, they probably will earn a badge for ironing. If somehow they have missed that, this is the opportunity to learn. 

If you have a portable ironing board, help them determine a good place to set it up. Consider which hand is dominant for them. Most people tend to iron with their dominant hand. Determine the direction of the ironing board. Also, consider the location of a plug and the amount of foot traffic in the area where you want to place it. If more minor children and animals are around, you may want to consider a room where the door can be shut. 

Once you have determined the place for the ironing board, it is time to fill the iron with water. A measuring cup with a pour spout works best for this part of the activity. This way, the measuring cup is carried to the sink for a refill instead of the hot iron. Plug the iron in and turn it to the temperature needed for the garment. Make them read the label. 

Spray the starch lightly over the entire garment. Spread out the garment on the ironing board so that it fits snugly, and that part of the garment can be flattened with their hand pretty easily. Use the iron to press that section of the garment. And keep turning the garment until it is ironed completely. Know that the arms and legs of a garment have a natural fold and will need to be spread out using the broader part of the ironing board. I usually iron this part of the garment last so it can be hung up right after it is ironed. 

Start with one or two garments at a time. To celebrate this milestone, have them iron a nice outfit and let them decide on a nice place to go out to dinner.