A successful illustration isn't just visually appealing; it makes a strong visual statement which clearly expresses the artist's intentions. Aside from colour and composition - two fundamental properties of the visual arts - the individual style of the artist is also extremely important. But when working commercially, an additional requirement comes to the fore: content. When an art director hires an illustrator, they choose him or her as much on their ability to convey a message as on individual style.
First off, consider what the illustration needs to say. Will the viewer be able to pick up on the concept at a glance? Are there secondary elements that will support the primary visual elements and help communicate the concept more clearly? Keep all of this in mind when presenting your idea to a potential client. And don't forget about those fundamental rules of colour and composition.
This tutorial focuses on an illustration by Derek Lea, originally commissioned by a pharmaceutical publication to illustrate a feature on insomnia. It detailed the adverse effects of the illness on sufferers who felt trapped by their condition.
The primary visual element, the tired face in the window, conveys this idea at a glance. The clocks, pills, books and other objects support the primary visual element by adding more literal elements to the mix.