Man, those were the days in those Frasca's. The number one thing in my teachings is the Scan. If their scan sucks from the start, then they are done once you start failing items. If their scan is based off of one instrument too often, then there's your first target to fail. Then just keep going on whatever they are relying on the most and whittle them down to minimum instruments. I don't think you can accomplish this in just one lesson. But developing the scan that works best for them is also a hard part, because instructors always teach what works best for them, without consideration to what might work best for your student.
Take some notes their next session, see what their crutch is, and try and balance the student out on their scan so that "when" something happens they can adjust without any complication.
Good Luck
**Btw, is there going to be a fly-in again this year? I didn't make it last year because the weather went to crap and I didn't feel like taking a pleasure flight without it being fun.