The first step of Narrative illustration is always to read the text. Then read it again, and again, until you have a strong understanding of it and what it's trying to do. This is important to the illustrator to help them start to create; there’s no point drawing a beautiful garden if the text is on sea life. Understanding the text can then help lead the artists to what research is required, and help them start the process of creating.
Materials and colours play a large role in the overall illustration, and it's important for the illustrator to choose them carefully. Ann Witherridge wrote in her blog, “The relationship between the artist and their materials. As with a musician, knowing your instrument is key. I have spent many years practising and teaching drawing and oil painting.”
As illustrators, the materials we use to create our drawings are vital. You can convey a lot of tone with your choice of material. Trial and error is important to the process and materials. Testing out different materials helps the artist to further understand the story they are telling.
Illustrators should have a good grasp on drawing skills, as recognisability plays a part of storytelling, especially in children's books. The audience has to be able to understand what's in the image and what it's trying to tell, otherwise it begs the question, why include this?
Having a good grasp of your materials as well helps, such as using watercolours and being able to incorporate a wide range of skills in this medium.