When observing the horse's movement rough stoney ground is good to trot them on.
When turning the horse the leader should be on the outside of the turn.
The leader should keep a loose lead rope so the head movement can be seen.
Dragging the hindleg toes is not a concern, as it just means the horse is lazy.
"Brushing" is when one foot knocks on the opposite leg.
Overreaching is when the legs swing outwards, mostly seen in the trot.