If you have never painted watercolors before, you may need to produce some additional carbon copies to practice before trying to make the final piece. Remember, painting with watercolors requires a lighter touch than other forms of paint. Paint lightly and practice with several drafts to develop the skill. However, there are many children's book illustration styles that the experts adhere. You must choose the one which suits the best with the project and that’s really important. You must not choose the style that doesn’t makes a positive impression. What do you think is the best style for beginners?