Like I said, Irock, even a or even a 'dot' works.
Just try and see if you like what it produces. If so, find more ways of using it. For example, you want a signature added to every work you make? Then draw the signature with any brush you like over the canvas, making sure the background is transparent, and then save it as a brush. Make sure it's in a size that's not too small or too big; just enough to fit in any work you make.
You could create stars, sparkles, and other things in your own style, make them brushes, and re-use them whenever you want.