After forty years of teaching I have further realized how important it is to organize a lesson based upon the keys being used for the various pieces being studied.  I am a firm believer in the importance of scales in the study of music. In the past, however, I would begin a lesson with the newest scale being studied followed by one review scale.  Following that warmup, I would move to working on a violin study and then eventually, working on the pieces which have been selected for this student.

Garth Williams
Over the past ten years I have changed my approach to the organization of my lesson plan for each student.  I do still highlight the newest scale being studied and will work on that particular scale using different bowing strokes and slurring combinations.  I then, however, progress to the study being highlighted in our lesson.  Before playing the study, however, I will choose the major or minor scale being used for this particular study.  My reasoning behind this is to emphasize the importance of the different finger positions for this particular scale.  Once we have highlighted this scale with a few different bowing patterns, we would then work on that particular study.
Once we arrive at the pieces on which we are working, I follow exactly the same format as I have done with the studies.
I will first begin with the scale being used for this piece, emphasizing some of the bowing combinations which we would need for this piece.  If this is a beginner and a new piece, I might suggest that we play the first phrase, using all the same length of note, totally ignoring the actual rhythm of the piece.  Once we have used the rhythms from the piece and the pitches found in the piece (using a quarter or half note figure, then we would present the first few phrases using the printed rhythms.  In the following lessons, I would tend to follow the same format but vary  it according to the progress being made. I have found, that using this new and more varied approach, my teaching has become far more productive than in the past.  In addition, I am much more able to retain the attention of the student with whom I am working.  If you are new to teaching a stringed instrument, give this approach a try.
As always, the matter of practising comes into play when working to achieve a goal, no matter whether it is in sport, art, music or drama.  We are all required to practise! At the beginning, I encourage parents to begin the practise regime gradually.  A young student is not used to holding the instrument for any great length of time.  So I usually suggest 10 min. twice a day, the first session should be first thing in the morning, when the young person is fresh.