Ever find yourself redrawing a pattern, or shape more then once and think to yourself, This would be much easier if i had a brush of this shape'. Well this tutorial will help you with just that.
1. Open a new canvas and draw out the shape you would like to have as a custom brush.
Tip - Make sure your not drawing your brush on the background layer. So create a new layer before you start drawing out your brush.
2. Now that you have drawn out your custom brush we need to make it just that, a custom brush. With the layer on which you drew your brush selected, click edit -> Define Brush Preset. Name the brush what you want and click ok.
3. Your brush is now ready to use, it will be located at the bottom of all your other brushes, so just scroll down and you should see it right on the end. This is really useful when doing pixel work since redrawing tough shapes dot by dot isn't very fun.