Muscle memory comes from repeating patterns. The most effective way of doing this is with exercises(scales, arpeggios, LaRiviere, etc.) and etudes. Exercises get boring fast, and I much prefer etudes. A good etude picks a pattern and works it to death. This is how you develope an arsenal of muscle memory patterns(octaves, triads,thirds, fourths, fifths, etc.) that are useable in helpng you to learn music. Use a set of etudes like the Bochsa op. 318(40 easy etudes) and play pieces that are compatible with the etudes you are learning.

When I teach a student, etudes and exercises take up about 1/3 to 1/2 of the lesson material, depending on other factors. Sometimes the student will go several weeks with no etude if the piece they are working on is a good substitute, such as a Bach transcription, or say Hasselman’s La Source(which by the way is subtitled ‘Etude.’). Try to use etudes as the main source of the technical material you work on. Carefully pick pieces that repeat a pattern(like La Source) and functions as an etude. Most pieces at all levels don’t repeat any pattern enough to form muscle memory for that pattern, and so pieces are not the best place to develope technique.

I find many etudes boring and prefer to do repetitive exercises. Why? Because I don’t have to think about the notes after the first time through, so I can concentrate solely on what I am trying to improve. If you are talking about developing muscle memory in learning repertoire, repetition is the key, and to break it down into musical syllables small enough to absorb, such as half of a measure. You must repeat it at least TEN times CORRECTLY, to make it stick. If you make a mistake, you have to start over. That was Miss Lawrence’s rule, which she delighted in. I think that was play to her. She loved the process. So, if you do it seven times, you will learn, but the last three lock it in as do any extra repetitions. For an adult professional,

You have to keep going. Muscle memory is only the first step. Starting in different spots, counting out the beats as you play, focusing on dynamice, phrasing and other interpretive details all engage the mind. Then you put it away. In a year or so, you pick it up again and start over, put it away. Maybe the third time, if you’re lucky, you have so assimilated it that it is second nature now, and you can only think about how to perform it, perfectly control all the effects, and be able to repair every memory slip. Then you must perform it at least once, somewhere, for experience, and then it is ready to be repertoire. A long process, to be sure, but it works, and you keep rotating your stock like a kitchen. I first starting learning Flight in 1980 at Tanglewood. I learned the notes, we all did that summer, and no-one could get it past 104 to the beat. Many times I worked it over. All last year. Until I performed it, it was never secure. Now it is so much more controlled and feasible. I think I can reasonably expect to be able to perform it at the tempo marked of 152 in the future. One nice thing about learning pieces like that, or the Variations by Salzedo: they improve your technique so much that everything else is improved.