Have a Wacom tablet? Then why not control the opacity of your brushes using the pen just like pencil and paper. This video shows you how to set-up Photoshop CS4 brushes to respond to brush pressure on Wacom tablets. The harder you push the more opaque the brush will be. A bonus at the end shows how to set this globally across all the brush presets with one button click rather than setting up on a per brush basis.
I want to give a big thank you to Lisa Sage for pointing me in the right direction on the global brush setting, Lisa is an amazing artist and you should visit her web site at http://www.sagefamilystudios.com.
Have questions or comments? Why not drop by the UIBuzz forums.