Came from a book of all places.
I didn't grow up with a plethora of riding coaches and parents who'd support my riding ambitions.
My parents preferred I was a casual weekend rider instead of a die hard equestrian determined to make a living from it. They got me lessons (at my begging) for a year to learn to ride. But it wasn't till I was 17 and was a working student that I could work for another year of lessons and show a few times.
Not exactly my idea of how I wanted my life to go. I never had a "home-barn". I never had a coach as close as a friend or even a fellow rider as a friend. I never fit in at any barn. I was always different.
But with all that time I didn't spend taking extra lessons like other kids or showing every weekend like all the other teenage girls at the barn I learned a lot valuable lessons. I became self taught. And I got to read and ride. A lot.
Book after book I searched and searched for a method of horsemanship that worked. I learned quite a bit of many different methods but non that worked on all horses all the time.
But then I read the best piece of equestrian advice I ever heard.
"Do what works."
Of course this excludes abusive tactics and anything possibly harmful.
This advice catapulted my horsemanship to a deeper level. I was able to start thinking in terms of practical, personalized problem solving rather than "what would trainer so and so do?". I could think, ride, and train for myself.
I learned to take the time to learn the subtleties of each horses mind rather than treat them as a machine like some people do.
There is no one method to fix a problem or train a horse. It's up to you to perceive what is needed and adjust accordingly.
Some horse respond well to natural horsemanship, others look at you like it's a joke. Some take the generic ques for certain gaits and movements, others prefer something totally different.
They are individuals and certain things make sense to some and not to others.
Bottom line is Do What Works.