My first couple of hours dual was with a gent going for his instrument (did my II as my initial). My problem was that I talked way too soon and wouldn't let him make any mistakes. We did a lot of work in IMC and it wasn't common for us to have to go missed where ever we were practicing because of low weather (thankfully I had great instrument training and a great II who exposed me to many [relatively speaking] of the elements so I was comfortable teaching in these conditions - not meant to come across as a pompous or overconfident attitude or anything). After a few hours, many of the mistakes he was making were not being rectified, so I finally decided to shut my mouth and say whatever needed to be said only when it had to be said.
This one was the most memorable: We were shooting a full procedure VOR approach into an uncontrolled field. The weather was about 1500 and 3 miles. He cut his procedure turn a little short and he had his hands full making sure we didn't blow through the final approach course. This is one of those approaches where the nav-aid is on the field and we designated that when we were established inbound as the time when he would lower the gear and extend a notch of flaps and turn on the runway lights. Yeah, he missed those steps and I told myself I wasn't going to say a thing until I had to...he needed to learn this lesson.
He got behind enough where this was going to be a good lesson learned, but not too far behind. I bit my tongue very hard because I wanted to say something as we continued on the approach with the gear and flaps up. We broke out of the clouds and per our usual agreement, I would tell him when he could look up. About a mile out I told him to look up, he saw the runway and reduced the power to idle and began the final descent to land. At 400 feet I asked him, "All set to land?" He said, "Yep!" I said, "ok, then." At 200 feet I told him, "Tell me what's wrong and show me the way you're going to fix it." He froze like a deer in the headlights. I said, "You have one second to go around before I take it so we don't make a lot of unnecessary noise when we hit the runway..." He still couldn't figure out what I was talking about and at 100 feet I took the throttle and yoke (he immediately let go) and started the missed approach. I asked him to retract the gear and flaps for me. That's when it hit him (and that's when I told him had we been in IMC to minimums, he never would've seen the field either). Lesson learned and it's never happened again.
Just to note, I was never going to let him continue beyond 100 feet or anything unnecessary like that.
I hope this fits in with this thread.
Take care,
Greg