The aim of this work was to gather different perspectives on the "key ingredients" involved in creative writing by children--from experts of diverse disciplines, including teachers, linguists, psychologists, writers and art educators. Ultimately, we sought in the experts' convergence or divergence insights on the relative importance of the relevant factors that may aid writing instruction, particularly for young children. We present a study using an expert knowledge elicitation method in which representatives from five domains of expertise pertaining to writing rated 28 factors (i.e., individual skills and attributes) covering six areas (general knowledge and cognition, creative cognition, conation, executive functioning, linguistic and psychomotor skills), according to their importance for creative writing. A Many-Facets Rasch Measurement (MFRM) model permitted us to quantify the relative importance of these writing factors across domain-specific expertise, while controlling for expert severity and other systematic evaluation biases. The identified similarities and domain-specific differences in the expert views offer a new basis for understanding the conceptual gaps between the scientific literature on creative writing, the writer's self-reflection on the act of writing creatively, and educators' practices in teaching creative writing. Bridging such diverse approaches--that are, yet, relatively homogeneous within areas of expertise--appears to be useful in view of formulating process-oriented writing pedagogy that may, above all, better target the skills needed to improve children's creative writing development. (Contains 4 tables and 2 figures.)