1. Create a new 165x165 pixel document and name it MyBrush. Now press D then x and fill the document (with white).Then select the polygonal lasso tool and make any selection you like. Press D then fill it with black.
2. Now go to the top menu, select Edit > Define Brush Preset... A window will popup, and you cna name your brush whatever you wish. Click Ok. Now your brush is available. When you use the paint brush, just click on the down arrow at toe top where it says Brush: scroll to the bottom and your brush will be there.
More Tutorials: 
