Start out by creating your shape on a new layer. Make sure the background is black and the shape is on a new layer.
Press “D” to reset your colors, and use Filter>Render>Clouds on the background layer.
Now select the Polygonal Lasso Tool and set Feather to 30.
Select your fractal layer and make a selection around it with the Polygonal Lasso Tool.
Go to Edit>Select Brush Preset. Now delete your layer and clear the
background layer so it’s like you are starting from scratch again.
Next select your new brush with the Brush Tool and click the Brushes Tab. Use
the settings in the image.
Now you can brush around on your empty canvas until you get a satisfactory graphic. There you have your custom brush! Use the same Polygonal Lasso Tool technique to extract any other image and use it as a brush! Enjoy!
