I continue to have incredible success using See Saw Swings to help students at all levels of development. With more advanced students, I have them play the first pages in third position and fourth position. Sometimes they cross strings; sometimes they shift. Because they are reading notes while trying out different positions, it transfers to pieces like La Cinquintaine and the Vivaldi a minor concerto.
And it builds confidence.
There is nothing else on the market similar to See Saw Swings. If you try it with your students, you will discover a motherlode of technical riches. How can something so simple bring so many benefits? Precisely because it is so simple.