It is true that nothing can substitute for time and experience hands on, as Kevins is saying, but not everyone has access to that sort of lifestyle. And IMO there's nothing wrong with also reading. I mean, when I read something interesting in a book about training, then when I go out to the horses I see them in a different way and it can really open up growth..
I am not a killer rider at all and will never be one. I am too old to start on that, but I never stop increasing my awareness of horses.
It's really a matter of watching them. Their way of thinking is very changeable, and very present. Spend some time watching them and ask yourself every 2 minutes, "where is his thought now?"
And when you work with a horse, and you apply pressure, try for the smallest amouth you can to see a "change". It's a change that you are looking for.
When I ask my horse to move over when I am tacking, I often put a little pressure on him (not actually touching but using pressing on the air with my hands toward his hip) and wait until I see him THINKING about moving over in response. THAT is a change. Moving over is a change, too, but even him thinking about moving over is a change.
So, when I see him thinking about moving, I stop pushing and see if HE can carry out that thought on his own, without me actually pushing him all the way to a step over. If he doesn't, then I removed the pressure before his thought had really set into "step over'. In which case, he was not really listening, and I need to speak louder and longer.
That kind of feedback loop is somthing that a horse person can spend a lifetime improving and the masters are so subtle at it that we cannot even see it.
I wish !