In this modern age the average horse person has access to a wealth of information. From magazines to books to online videos and dvds you can learn just about anything. This near limitless amount of information has gone a long way in helping everyday horse owners improve their skills and general horsemanship, but there are still some things that cannot be learned without the guidance of a skilled trainer.
I like to say that horse training is both an art and an science because unlike baking a cake you cannot just follow the directions and measurements on the package and have everything turn out perfect. Training a horse requires timing and for lack of a better word feel both of which involve constantly changing variables.
When I start a horse (I hate using the word "break") I follow a basic formula, meaning that I know what I need to do at each stage to achieve the next. I know where my horse needs to be with one skill/behavior in order to successfully move on to another. This is the type of information found in every magazine article, book, and dvd. These media sources tell you the steps you need achieve your results but they only share the big picture.
Beyond the basic formula my training takes on art like form where I am constantly using feel and personal intuition in addition to timing to achieve the results I desire. I know that every single horse I ride requires a slightly different approach. With feel and intuition I am able to determine how much each horse needs to give and do on any given day to be successful. Where Horse A may be mentally able to learn how to yield his hindquarter and his forequarter in one day, Horse B may only be ready to yield his hindquarter a single step. This doesn't mean that Horse B will never achieve the level of Horse A it just means that a single step was all that Horse B could handle that day. Tomorrow Horse B having been given time to think may surpass Horse A on the next lesson. I train by reading how my horse feels and by learning how he thinks. Using my sense of timing I release and reward according to the individual and how he is performing each maneuver on any given day.
The problem with intuition, feel, and timing is that their only constant is that they are constantly changing. You may start at one level of timing at the beginning of the ride and finish in a completely different place. You have to know when you need to go back to zero and when you are ready to zoom up to sixty and this can fluctuate back and forth in a matter of minutes and at times even seconds.
Only through experience, trail and error, and guidance by someone skilled in the art of training are you able to develop a true sense of feel. While it is theoretically possible to achieve these skills without outside help working with someone is the fastest and most painless way to achieve your training goals. Remember that every great professional rider has or has had a great mentor. Greatness is rarely achieved alone.