sidelanes.com

Im using Photoshop CS3 to make this brush.

1. Open a separate file that is the size that you want your brush to be. It’s often best to make a large file in case you need the same brush to be larger down the road.

Now convert your document to grayscale; White pixels will be transparent, black will be opaque, and everything in between will be a semi transparent gray.

2. Now go to Edit > define Brush Preset and your brush will appear at the end of the brushes pallete. Play around with brush presets to get the look you want.

For more detailed information, here’s a good blog that describes the custom Photoshop brush making process in a little more detail.

Here is a full set of premade custom Photoshop brushes that I really like. If you don’t find what you’re looking for there, here are a few more brushes you might try.