One of the aspects of a properly balanced practice approach that is very often overlooked is review. The common tendency of most students is to focus on "new" things to play, even if last month's or last year's "new" thing was never properly learned. There are a few reasons for this:
You must examine yourself, and see where you stand with all of this. Ask yourself these questions:
We are, of course, looking for yes answers here. If you come up with "No's", "Maybe's", or "Um, could you re-phrase the question", then you need to take serious heed of what I am saying.
Now of course, we must, on a regular basis, take on new material. But we must also, on a regular basis, review old material. Let's look at some of the reasons why this is so.
Often, as I give a student something new, I will tell them "it is not possible for you at the present level of your development, to learn this piece (or song) well enough to be able to play it the way it is supposed to be played. Consider this piece like a tree you are planting. It will take a while, maybe a year or two, to grow fully. Each time you come back to work on this again, each time you review it, it will grow taller and stronger. Right now, we are just going to "plant the seed".
We then work on the piece or song or even exercise, until a "first goal" is reached. A "first goal" is the level of proficiency that I feel the student is capable of achieving at their present level of development. Of course, this means the level they can bring the music to IF they do their absolute best in terms of practicing it. This may take two weeks, it may take two months, it may even take 4 to 6 months before I feel the student has taken it as far as they can.
At this point, they can stop "working on" the music, and just "play it". It can become part of their repertoire even if it hasn't been brought up to performance level. Playing it will keep it in their fingers, and in a general way, it may even improve just by playing it, but usually whatever technical problems still remain will remain.
Whether the music is still played, or put aside, the point is that at some later time that music must be re-visited. Those technical problems that were beyond reach must be gone back to later on, maybe six months later, maybe a year. If the student has been developing properly they will be able to take that music further, beyond their first goal.
It is this process, repeated over and over, that builds a solid repertoire, and a solid player.
A good example is a student of mine who was new to fingerpicking. We worked on "Dust in the Wind" for about 6 months, and I mean the whole song as a guitar solo, chord melody arrangement, including transcribing the violin solo for guitar. He learned it pretty well, but it broke down in a few places due to left hand problems and the fact that he wasn't properly trained in classical right hand technique ( we had been doing mostly electric and jazz up till then).
We then spent about a year doing classical studies, and recently, I told him to review "Dust in the Wind". What a difference! He now can play it very fluently, and it is extremely satisfying for both of us to see the progress that was made. This is the way it should be for all of us.
Robert Louis Stevenson said "A man who holds the same views at forty that he did at twenty, is a man who has been stupefied for twenty years!" I say, a person who plays a piece of music at the same level now as he did a year ago, does not know how to practice and does not know how to create vertical growth in their playing ability.
At any given point, there should be a "new you", when it comes to life, or guitar. When this "new, improved you" reviews an "old piece of music", it should become a "new, improved, piece of music" once again.