Gavyn and I have been working on stamina, playing pieces that are a good bit longer than some of his other repertoire and Also music that jumps from one string to the next quite quickly and suddenly.
Jean Francois' Soleares is a good piece for developing these aspects of technique!
I have many students of varying ages, and standard, I have added a play list to my You Tube channel specifically for my students to take to the screen and enjoy sharing with you their performances.
I hope that you will take the time to have a look and offer considered and positive encouragement to some very talented and committed individuals.
Here is the link to the complete student playlist: