There's a beautiful old Islamic saying - Handwriting is the jewellery of the mind, fashioned by the hand, from the pure gold of the intellect."
So, if your child is trying to learn something, encourage them to write down the information. This is not the same as performing penmanship. The quality of the handwriting is not the object in this exercise and in fact, concentrating on the formation of the letters will detract from the learning of the content. So, just encourage them to let their pen flow freely and read what they're writing out loud at the same time.
And it works for we adults too!