In some cases, we were given time to read the book simultaneously as we were designing it. We were commissioned to 'invent' diagrams, and for the younger students series (AAT) to research for pictures and write up captions for them.
Marketing and especially creative marketing is a subject that fascinates us so we really enjoyed the whole procedure.
Rumour has it, that tutors of the new-designed books have asked PowerPoint slides with the above illustrations from the publishers.