Everyone always says keep doing it, it will get better. Keep trying, keep practicing. This is true, but only to a point. Practice does make perfect, but only good practice works.
Imagine. You are teaching your horse to canter. Each time you ask for canter, you put your outside leg too far back and your horse bucks into canter. What do you think will happen if you keep on doing the same thing? Your horse will learn that when you put your leg that far back he bucks into canter. You have practiced, you have followed the instruction, but you have only practiced the wrong aid, so it hasn’t worked.
It would have been better in this instance to think, I am struggling with this, so I will wait until my next lesson and then check I am doing it right, rather than keep on doing it wrong. Maybe you could have just practiced your walk trot transitions for the week till your lesson instead.
Of course sometimes we aren’t sure whether we are doing right, but if you aren’t sure, then see whether you think you are getting the right response. Are you teaching your dog to sit? Is it sitting properly? Or does it keep lying down instead? Are you teaching your horse to wait in his stable doorway without rushing? Is it working? Most the time we know when we are doing it right, as we get the right reaction. Be mindful of whether the result you are aiming for is the same as the one you are getting.
Training is fascinating and endlessly rewarding and training using repetition is an essential part of that training, but it is vitally important to make sure that you are doing good practice not bad practice, as only perfect practice makes perfect.