What I don't like in an instrucotor or coach:
1. Crazy long explanations that lead nowhere: I'm not an intermediate skier, I know how skis are supposed to work. I know of enough drills to correct myself, being a coach myself.
2. No demos in the course whatsoever: my line in slalom might not be the best, but how about showing me the best line? Don't do it fast, just show me where I should stand approaching the damn gate (bitter much?
3. No preparation: lessons should be planned in advance, period.
4. Waiting in line for video.
5. Crazy SL courses with pins and flushes when several people in the class haven't raced ever.
What I don't like in students:
1. When they think they know better than you (no, my hip isn't back! Pole-plant isn't useful in modern skiing, etc.)
2. Intermediate, or even beginner, students expecting video. IMHO, video is for refining skills. You don't need it when I'm showing you how to pole-plant or carve: visualization is key here. If you can't see yourself doing the movement, how will seeing you not do the movement be helpful?
3. Students who bitch in your back about frivolous thing (not talking enough, too much talking, doesn't dress nice enough, etc.).
4. Students who come with a goal in mind for the lesson (this is usually very good) that is way over their head, such as mogul skiing when they are crazy in the backseat on the tamest blue runs.
5. Students who bitch about drills: I didn't become a good skier only freeskiing. It takes effort, patience, and a lot of dolphin turns
. Suck it up.