I use this as part of the art lesson because with younger children it goes really quickly.
Step one - get the children to draw a hand
Step two - get the children to draw a their hand WITHOUT looking at it at all. Try and draw it in one go without lifting the pencil. This is difficult for younger children. If the child struggles not to look at their hand , a divide between the hand and paper might work or place the hand in a bag.Step three - draw your hand with both looking at the hand and looking at the paper. Carefully observe and translate what is seen onto the paper.