Over the years I have reviewed and worked through many DVD's, The ones that I consider the most influential and comprehensive as full training courses to application techniques aimed at from New to Advanced airbrush users are:

 

The Power Series by Daniel Power

available from:

 

Illustration Cheap Tricks & Special effects by Michael Cacy

available from:

 

Ultimate Airbrush Effects & Techniques by Terry Hill

available from:

The Secrets of Airbrushing True Fire (Part one and Part two) by Mike Lavallee

available from: