This dual brush is based on the cloudy background brush from our class project and a semi-translucent set of daisies brush I had made for myself a while ago. Each color above is the same brush with a different combine mode. From the bottom up: difference, normal and overlay.

Here I combined several layers of this brush and gave a shadow to one of the layers.

And here I added some stamps of the original flower brush on top of all. The brush is translucent in the centers because it was made from a colored in original and all the places that aren't originally black or white in the brush become some level of see through, depending upon the value of the original color.

Great class, thank you!