In this little tutorial I am going to show you how to create a custom brush.
First you need to either make your subject image or find one online. I found this one of link from Deviantart.
Next you need to Desaturate the image. Go to Image > Adjustments > Desaturate or SHIFT+CTRL+U now you should have a nice greyscaled image.
Now that you have the greyscale we need to give the image a bit more contrast. Got to Image > Adjustments > Levels or CTRL+L set the input level to 92, 1.00, and 225 and hit OK.
Your Image should now look like this:
Finally go to Edit > Define Brush… name the Brush Link. There you have it a quick but impressive looking Brush. Here is an example of what the brush looks like: