Oh so you dont believe in circling in tight circles as punishment/correction? Why not?
I will never lunge her again when correcting her, I know thats forsure. I wonder if what i did a few days ago was damaging to our partnership. She was very scared, I made her scared, Im not proud of it. I will not do it again.
It all just depends on what behavior you are trying to correct. Generally a correction should be the opposite of what the horse thinks they should be doing. So if the horse thinks she gets away from pressure by turning into you, and is running you over to do so, applying pressure that sends her away from you, in the other direction, and releasing when the horse moves away, would be the most effective correction.
No correction is very effective if it continues after the behavior has stopped. You want the behavior to stop, so you need to release/reward when it does.
Your trainer wants you only turn your horse away from you, because the horse is anticipating that she will find release by coming into you (which she does, because you move out of the way to avoid being run over). So what she is having you do, is reconditioning the horse to anticipate release being found by stepping away from you. If, you do that for a while and find that your horse starts trying to turn away from you without asking, you'll have to switch it up and make sure that you sometimes turn towards you and other times away, so that your horse can't anticipate.
While I think it's important that you stick with the methods your trainer is teaching you, as that is what you are paying her for. I don't really tend agree with using tight circles as correction, as it just isn't quick or concise enough for me. That's not to say it can't work, but for me it is not the most effective way to correct. If I had a horse running their shoulder into me, or even just not stepping their shoulder away from me when I asked, I would take the end of my lead rope (or longe whip) and pop them in that shoulder to send it away from me. It would be quick and concise, my body positioning wouldn't change and I wouldn't be taking the horse off task. The very moment they moved their shoulder away, we'd go right back to what we were doing.
There are tons of different ways to correct a horse. In all reality, it's not about the correction, but the release. THE MOST IMPORTANT THING is what you release the horse to. I could teach a horse to spin a hole in the ground every time I pulled his tail, by making sure I released when he made the movement I was after.
That being said, thousands of years of people training horses has helped us understand and develop cues and corrections that are most easily understood by the horse and bring about the fastest, most solid result.
For me, I could teach a horse to move their shoulder away from me, in a matter of minutes, by applying a direct, quick, concise correction, in the form of a slap on the offending shoulder with the right timing and the right amount of pressure. I would imagine it would take me a bit longer to get the same message across by turning them in tight circles away from me, but I can see how that might work. If your timing and feel isn't solid enough to apply the quick correction effectively, then it may be a better option to correct with the tight circles, I don't know. I do know though, that I wouldn't be doing two, maybe not even one full circle, just a quick step or two and then right back to business.
Sometimes making a horse 'scared' is necessary to send a message. The reason being, is they will remember those moments better than they will little corrections that were more just minor annoyances. There are times when the horse acts in a very dangerous manner (rearing, bucking, biting, kicking, striking, etc) and you need to make sure they don't forget the consequences of acting in such a way. But even still, all the same rules for other corrections still apply -- timing, quick and concise - get in and get out then go back to business, consistency, etc. The only difference is the behavior was a big deal, so the correction needed to be a big deal. Remember the correction needs to fit the offense.
If I was leading a horse and they reared, I would send them forward with as much energy as I could. Rearing, is usually a result of a horse's feet getting stuck and them either thinking they can't go forward or refusing to go forward, so they go up. A horse really can't rear if they are moving forward So, the correction that makes the most sense for me, is to send them forward very quickly. The nature of the fact that I'm on the ground, means that they will have to go forward around me. I would only do this for a couple of seconds (though I would make those seconds count by really sending them forward). If I was riding when they reared, I'd just send them hard forward straight.
The other time I would move a horse around me as a correction is if their feet got stuck in reverse, because again the opposite of that is going forward. And again, the only reason I'd have them go around me, is because I'm on the ground. If I was on them, I'd just send them straight forward. And again, it would be a quick, concise deal, not multiple times around me for a drug out period of time.
I would also consider this type of correction if a horse locked their feet down and wouldn't move anywhere, though it would depend on how I read the situation. I might choose to move them laterally instead, depending on the situation (though I would never try to move them backward to un-stick their feet, as that's asking for one to rear)
It takes time to learn how to think like a horse and be able to make split-second decisions about how to correct behaviors in the moment. As a novice, it is probably best for you to stick with what your instructor is telling you, so that you can condition yourself to be able to respond with good timing and not have to think about what correction is best. Once you get more comfortable with applying corrections and thinking like a horse becomes more natural, you'll be able to put more analysis behind how you correct in the moment. For now, just keep things simple so that you can get your timing and release right, as that will benefit you and your horse more, in the long run.