Tutorials In this Fretwork tutorial video, Joanna Levine offers helpful techniques and exercises to help you cross strings cleanly while producing an even tone.Joanna Levine discusses practice tips and techniques.In this video, Joanna Levine shares some helpful techniques and exercises to help you produce a full sound while maintaining control of the bow. Asako Discusses LH position to help with stretches to the 5th fret. In this tutorial, Sam Stadlen goes over a simple technique to help you acquire a secure but relaxed bow-hold.Joanna Levine discusses tone quality and sound production.