Thanks. We've been covering backing a bit verbally. As soon as son-in-law gets home from business travel, I'm taking him and daughter to a school parking lot with orange cones for some backing instruction.
I've been talking about clearance awareness, braking distance increase, looking further ahead than they're used to, trailer tracking (cutting corners - not sure yet how this toy hauler tracks but I'm assuming should be just like any other bumper pull) ... the hardest part is my daughter stripped the interior the day they got it home - sealing primer, zero VOC paint, wall paper, floors, faucet fixtures, etc - sometimes I think she's lost her mind :) and my son-in-law is still scrambling to put it all back together so we can go do some actual driving lessons.