Creating a Brush

Step One

Open a new image. The width and height is up to you, depending on the size you want your brush to be. Just make sure the image's background is checked in for Transparent like below:

Step Two

Now draw something you want as a brush. Make sure that you drew it black.

Step Three

Now click the brush tool (if you hadn't clicked it already)

Step Four

Now look at the icon on the right of all your brushes. Click it. (The icon is outlined green in the picture below)

Step Five

This box should appear. Choose a name, and press "Create."

Step Six

Then look for your brush and test it! :)