When using the Airbrush tool in Photoshop you can achieve a traditional airbrushed appearance by adjusting the tool options. To do so, double-click on the Airbrush tool. In the Airbrush Options palette, change the Painting Mode to Multiply and set the brush pressure to 6 percent. This allows you to gradually build up layers of color, and you'll have more control of the final outcome of your piece.
