So for my firefly (see last post) I needed a design on her thorax...something that reminded me of jewelry designs/etchings. So I went into Adobe Illustrator and created a design with swirls and strokes. Here's what it looked like.
Then I simply selected the object in Adobe Illustrator, hit Command C (copy), and then in Photoshop I hit Command N (for a new file), Yes, and then Command V (paste). It pasted the design onto a transparent layer. Then I hit Command A (for select all), then Edit-Define Brush Preset, name the brush...AND WAHLAH! the brush shows up in your brush pallet. Pretty darn awesome.
I know a lot of you may have been doing this for a while, but I never have. I've simply downloaded brushes from the internet. Now that I know how to make my own license free brushes, I think I'm going to have fun with this. Try it out.