One of the things I've noticed is that being on the correct diagonal seems to feel different (more right) than being on the incorrect diagonal - but I don't actually know what it is that I'm responding to with that feeling. The riding gets a little easier when I'm on the correct one, but I don't really understand why.
As it is, I'll have an idea that I am on the right/wrong one, but I feel like I need to actually check...and when my trainer took a video of me posting in the arena last week, I was horrified to see just how long it takes me to check and verify the diagonal, and how awful my posture in the saddle is when I'm doing that. At this point, I can tell about 70% of the time when I'm on the right one - I'd like to increase that to 100% so I don't have to crane my head over and watch the horse's shoulders!
I checked with my teacher to verify that it *is* possible to feel the right/wrong diagonal, but she wasn't really able to verbalize how you can tell with your seat. I'm hoping someone on this forum knows what I mean by this, and can shed some light on it?
The good news is that it doesn't seem to be any problem for me to change from one diagonal to another - that part of it, I managed to get right away. Now it's just figuring out how to know by feel that it's right, or that it's wrong & needs to be changed.
Also, is this something that will just be automatic after a while - where once you get some experience, you just sort of start out on the proper diagonal? Or is it something you're always having to kind of think about?