Put more bend at your elbow, keep your shoulders back, & sit up tall. Your hands should never cross over your horse's neck, and should always stay slightly widened (not touching together like in the 5th picture) & relatively even. You need to be bending by pushing her into your outside hand with your inside leg, regardless of what pattern you're doing (circuits around the arena, circles, serpentines, tight turns, whatever). The inside rein can be used in a take-give motion to help encourage her to drop her head or look in, but it should never be used as the primary aid, only as a secondary support system when you need it. In the 5th picture, it looks like your heel is slipping up & you are thrusting too far forward when you post. This can be caused by trying to push yourself up with the ball of your foot. I'd recommend dropping your stirrups and working on posting using only your thighs. Also, make sure you're keeping your leg around your horse, putting equal weight into both of your stirrups, and not letting your toes point out.