Hi pfepixel
I like both colleague's and Preston's approaches. Here is yet another
I just created some even spaced Paths over the blank image area (one path to two, then two paths to four, four paths to eight. etc etc) see first image. Then I just did a stoke fill on the paths after setting the Brush characteristics to random size variation in the Brush Settings panel for the second image. For the third image, I just added a brush scattering characteristic. Lots of possibilities to consider. Hope this gives you another "Path" to consider
John Wheeler
Screen shot of Paths created over image
Select all Paths and stroke only with size variation for brush
Image using size and scattering brush characteristics