Once they feel comfortable, form will come. Just keep them going. At first, work around mistakes and don't rip them out. Keep the lessons short enough so as not to lose the child's interest, and before the lesson ends, get them excited about what they will learn on the next lesson. If the lesson is too long and becomes too difficult or boring for the child, they may lose interest altogether.
Children often like to compete.
Explain to them that this is an individual learning event and how fast or slow one is does not matter. What's important is how much they are enjoying it. Be Patient Patience is probably the main ingredient for success in teaching, and this is especially true when teaching children. For instance, one instructor who enjoys teaching children suggests that when teaching young people, always dress comfortably. One successful technique she uses is she sits on the floor with the students standing behind her.