"Let's make learning fun for children!" has almost become a cliche for our generation of educators, children's book authors, toy and game designers, children's TV producers and anyone remotely related to children's education. We cannot ignore the role of a strong visual design in creating any of the modern day learning tools, whether they are early learning apps like abcmouse.com, khanacademy.org/kids or educational toy robots like Cubetto, Dash & Dot, Botley or BeeBot.
From baby years, children are exposed to educational toys and games that heavily rely on cute characters, stimulating colours, patterns and textures for tactile learning. As children grow older, their learning expands to more mediums besides toys and into educational board games, puzzles, video games, television, online streaming services and many more. At school, they come across interactive learning games, or good old charts and posters on the walls of the classrooms.
They're surrounded by beautifully illustrated educational children's books at home and school. They belong to a generation where several startups and established companies are trying to design new and more effective educational products for children and several Learning Scientists are attempting to understand how learning occurs in different settings.
Are your designs representing a topic in isolation or in a broader context of a curriculum? You might want to maintain a common design language for the entire curriculum around a topic, to support continuity/correlation visually.
In an educational environment, Visual Memory consists of pictures, symbols, numbers, letters, and words. As designers, the more we rely on design elements that can be "memorable" for the target audience, the better it can support the subsequent educational content to be recalled later.
The Age-range of the audience, their developmental milestones, complexity of visual information they can easily comprehend.
Where will your educational designs be situated? What are the surrounding cultures, trends, locations, demographics etc. Are there certain design styles that may appeal to this audience?
Make sure the visuals are clear and denote the meanings you wish to communicate as an educator. Gestalt principles are a nice, quick way to review instructional art/educational illustrations for any "applied" meanings.