What kind of student are we talking about? College, High school or middle school? I once visited Autodesk and they did workshops for kids and teenagers. What was cool was that there was a printout sheet with instructions (much like Lego) and they could pick from a few different models. The objects where things that they would want, like a iphone stand for a table, a fish with bearing rings and a back scratcher. I think what you make, and also that its not too time consuming (30mins or so) is crucial to not loose patience.