Determine your childs level when it comes to coloring. Some color books provide large coloring spaces making it easier for children to color the page, stay in the lines, etc. As the child gets older, their skill level for coloring increases as well, and the difficulty of the book may as well. Some coloring books come with written instructions, and other games, such as a dot to dot, or a maze. If you want to keep your child happy, and still challenge them, choose coloring or activity books in their range or level, and do not frustrate them with books that have too small of pictures, or too many spaces to color, or written instructions.
The lines of your coloring page are the rules you need to share with your team, share with them the boundaries. They are more likely to stay with in the lines if they know that they exist. Next by holding the work up for group and team acceptance they become their own self policing force. They can set self expectations and make constructive self criticism as well. The reward is acceptance and recognition from the team, an old saying is that a person can starve without any feedback, but only needs one good compliment to be filled to overflowing.