I use a comparison of driving a car similar to riding.
Imagine making a turn in your vehicle.
First, you'd use your blinker or turn indicator.
Then you'd turn the steering wheel a specific amount to get the tires lined up with where you want to travel.
Last you'd add a varying degree of the gas pedal.
With horses, it should be the same.
Give warning as to where you'd like for them to move.
Turn their head towards the direction making sure the are looking and thinking towards the designated spot.
Then add energy to have them move towards where they are looking.
Most folks with their horse have no blinker, very little steering and a whole lot of gas pedal.
Then they critique the horse for not getting it right.
In this shot, I'm using my left "blinker" to get Sally's thought to her left, as seen with her left ear acknowledging me.