Free Stuff!! (more to come, so check back)
Here are some free harmonic exercises, and a tutorial to go along. Harmonic Studies PDF
Here is a handout explaining some basic extended techniques:
Extended Techniques PDF
Diminished scale exercise based on Taffanel Gaubert:
Diminished Scales PDF
Singing and playing exercise based on Reichert:
Reichert Vocalise PDF
Collection of intonation exercises:
Intonation Exercises PDF