One of the most common way to learn an instrument is to seek a teacher. If the teacher is worth his asking price he will have a method. He might advise to study heavily technique for example. Or he might emphasize interpretation and have a whole bunch of exercises on the subject. A really good teacher will have a big catalog of assignments (preferably fun and interesting) to propose on any subject at any level.
If we were to witness a string of lessons with such a teacher we would see that from week to week there will be a succession of drills on technique. Some of them might involve octaves, replaced by some thirds, followed by some trills, etc. A concept is studied, then it’s off to the next, and, more often than not, that first concept is not to be checked again for months. Do you see the problem in these proceedings? The knowledge doesn’t stick. Yes, a lot of ground is covered, but the information doesn’t stay planted in the student. If you go too fast from one subject to the next, you lose the skill you’re trying to master. So, the question becomes, how should we approach this sticky necessity: the reviews?
One way could be, as you conceive the material, to make it enjoyable and engaging. It’s also primordial that it’s never labeled as “review”. Review” sound like the left over in the back of the fridge that nobody wants to eat. Names like “challenge” or “ultimate” or (why not) “rev” are much more appealing. The review then look like that fresh prime steak you just got at the grocery store.
And, as you go over the same subject many times, the knowledge begins to melt into the very fabric of your brain. It becomes more than something you happen to know, it is now a part of you. In other words: you have accumulated knowledge.

