Some say that making your own brushes within Photoshop can sometimes be hard.  So here is a tutorial which will show you how to make your own brush:

    http://www.time2photoshop.com/complete-guide-to-makign-fractal-brushes/

Personally, I would have used different types of fractals, as opposed to the ones created from the software in the tutorial.  But the basic instructions might be useful to people reading this Forum.