Below is a flow chart I scratched out to basically outline my thinking process when I run into a training challenge.
You may wonder why I have included an action plan for if the horse is doing what you want. It is because this is one of the areas that I end up causing myself the most frustration. It sure seems simple to just smile and be happy if your horse is doing what you want, but it's not! That is usually when it's irresistible to keep asking for more, and more, and more, until the horse finally has to scream "enough already!" Asking for more from a horse that is already trying will teach them it is impossible to make you happy, and they will quit trying. If they feel like the only reward they get for a job well done is more work, they will lose motivation quickly. When a horse is trying to please you, take every opportunity to let them know you appreciate their effort. It will save you a lot of frustration if your horse stays motivated to do what you ask.
The three action plans for when things aren't going as desired are pretty simple, and they all depend on reading why the horse is struggling. There are basically only two reasons why a horse has any problems doing what we ask. The first is because the horse is over confident, the other is because the horse is afraid. The three different strategies overlap both types and you will notice some of the same symptoms under different strategies. Being able to decipher what strategy the horse needs in the moment is an art form I am still struggling to master.
Ask For More: A bore/distracted horse has trouble focusing on what you are asking because you are not giving it enough to think about to keep it interested. A horse can also be fearful/distracted. When they are busy spooking at everything, they are letting you know that their fears are more important than what you are asking. These are times is when you ask for more. Up the game so that the horse doesn't have time to be messing around ignoring you, or to keep its mind busy enough that it focuses on you rather than all the "scary things" around it. "Upping the game" can mean asking for more energy from your horse, doing the same task with more speed, or a series of tasks in succession. Asking for more means doing whatever it takes to keep your horse's attention focused on you.
Ask For Less: If a horse seems overwhelmed with fear they don't need any more stimulation to focus on what you are asking and can be terribly confused if we ask for new or more challenging tasks. Being overwhelmed can come in the form of being "dull" asking for too much can cause a horse to get sullen and stubborn. For either situation, rewarding the very smallest positive effort will help build the horse's confidence and motivation. Make sure all of your cues are slow, soft and deliberate, slowing down and getting softer gives the horse a chance to really think about what you are asking for and will help dispel any confusion caused by miscommunication. Asking for less is what builds trust and communication.
Ask For Something Different: Occasionally a task or technique just doesn't work! When that happens, ask for something different. Find something that you are confident that you can ask your horse to do that will make you both feel successful. There are situations that call for totally scrapping the plans you made for that day and doing something that is easier for you and your horse. Continuing to pound away at something that isn't working will only make matters worse. Giving yourself and your horse time to improve other skills will make it easier when you attempt the difficult thing again in the future. If things start to go South and you aren't sure how to salvage the lesson, don't be afraid to quit what you are doing and ask for something different.
Lastly, try to view your frustrating times as an opportunity to improve your skill set. As an example, when one of my horses had a rather challenging habit of bucking I would try to stay positive by thinking how much it was improving my seat and balance. What I didn't realize was that he was also teaching me to be very aware of my horse's emotions while riding and to be cautious about asking for too much before my horse was ready. Taking a positive view of the situation will help you to stay calm, objective, and flexible in your approach. Who knows what you could learn when you problem solve your way through frustration.