One of the most useful pieces of advice I learned long before Karate: Whenever you teach, always have a point! Decide what exactly your point is going to be, and then make sure for that session, that everything moves you towards that point. Good teachers do this instinctively.
If something does not directly strengthen your point, don't include it! It is nothing other than a distraction. It can be hard not to include all the information you have on one particular subject, but you have to be strong, and save that piece of information for another class when it is relevant to the point you are trying to make.
So, with application to karate, say the teacher asks me to take a blue belt aside to help them work on their one-steps. I've noticed that the student is hesitant in class, and awkward. So I decide that she needs to work on "flow", so the routine is smoother. As much as there is to teach about one-steps, if it does not directly help her flow better, I will not teach it at that time. I will only focus on certain things: snapping your hips, not for power today, but for putting your body in a good position for another strike. I won't focus so much on a lower stance, as I will for foot positioning relative to your partner. I may focus more on combinations of targets, and not accuracy for each specific target, Etc.
Another day I may work with her on one-steps again, but today she is less awkward, but is weak. Now I will go through her hip-snap, stances, and strikes all over again, but this time with the "point" of developing power.
Teachers that try to include every detail about every move often end up with confused and frustrated students. Good teachers know how to include those details which are relevant to what they are teaching, and who can focus on different points throughout the curriculum, and don't get stuck on one point over and over.