The youtube videos were pretty informative.
I noticed several things.
First, when picturing my posture, I am sure my hands are "higher" on the neck. I believe I am equal on both sides of the neck, but much higher than the wither. When watching the videos, the riders appear to have their hands nearly touching the saddle. Which, may explain why I feel I have to come up so high to "bring my hips through my elbows." My elbows are high!
Second, leg position. Some of the women in the videos had floppy legs and some had legs that barely moved at all. It was those riders who had the still legs, who looked the most effortless. I know that my legs are floppy spaghetti legs. One video stated that if your leg is too far back (or was it forward? Dang, I need to go back and watch.) either way, the leg position determines your forward position and if the leg position is wrong you will be off balance on the "up" and most likely sit back on the down (and sitting back in chair position screws it all to heck.)
This same trainer discussed center of gravity with the leg position. And how a rider tends to go higher up when learning and that screws up his or her center of gravity. By positioning the legs correctly and rising "just enough" to avoid the horse's bounce in the trot, the rider maintains a lower center of gravity and balance.
This trainer also talked about the position of the hands and balance and lower hands aided in balance.
Several trainers spoke about opening the knees, and opening the elbows during the post forward. I know I am clenching with my inner thighs, probably to my knees.
I am going to have to work that in my head a bit more. I'm not sure if I get the opening the knees bit.
I probably don't open my elbows. I am trying to feel the horse's mouth and I am probably stiff. I will have to relax from the shoulder's down.
Good videos. And you can see the type of student I am. The trainers who took the time to break down the what is happening gave me more of an aha moment than the trainers that just instructed you to what you should do.
If I understand why I am doing something it helps reinforce the how to do it.
Well, back to youtube!