Oh man, I've had a few instructors since I first started riding. My first instructor is a great lady who I still keep connected with. She was great for beginners but once I got older I realized I really needed a push and a one-on-one connection.
A trainer I had at serious showing facility made me ride and steer the horse without stirrups for like 20-30 minutes every lesson I've had. Man did I go home and not walk for days! Unfortunately my high school is three stories high, doesn't help much, hehe!
Those were private lessons and man did I get a workout!
My most recent trainer from last winter wouldn't let me get away with anything! If I was trotting with my feet dropped from the stirrups, I would try to rest my thighs for a couple seconds while she briefly looked away. But boy she could be tough on me! She also did record me riding a few times and that really helped me understand things that I'm not exactly doing correctly and it really helped me to correct my seat (which was my main problem).
But when I start this lease at this farm I found I won't have an instructor or trainer, so I'm all on my own this time around! Sorry to blabber. I could go on for hours about this kind of stuff