Defining what Speculative Work (Spec Work) is and for what reason it should or should not be done should be published here. Possibly linking to: http://www.no-spec.com/ http://www.aiga.org/content.cfm/what-is-aigas-position-on-spec-work-and-ethical-standards

Aiga's Letter to be customised to send to your clients: http://www.aiga.org/resources/content/5/7/5/8/documents/AIGA_standard_spec_letter.pdf