What makes toon furniture toon is its shape and textures--more specifically, it's colors.  You wouldn't want a nice leather texture on a toon sofa, but a nice red, yellow, blue or pink would scream toon and only if the dimensions were exagerated.  You might want to make the armrests of a sofa or loveseat large and flared outward etc.  Just think in toon and  you will create toon.