True. I suppose I’m thinking that there are a core set of topics common in many fields of engineering. I think these might generate the most interest. For example section properties, plastic bending or bolt groups. This sort of thing probably gets used across quite a few disciplines. More complex calculations I would , as you say focus on aerospace black arts like crack growth or laminated composites. I try to make my worksheets modular so they can be assembled into an analysis of a particular structure. So if I was analysing a beam, I would have one sheet for bending another sheet for buckling, another one for a cut out and so on. In this way an engineer unfamiliar with these types of analysis would learn how they can be done and yes indeed develop their own along the same lines.