Set the next parameters for each of the three demonstrated spiral’s elements:
Blending Options>Outer Glow 
We’ll get the same picture:
Download out of Internet a set of ready to use brushes for Adobe Photoshop, named
GVL Funky Flower Brush 
On this stage we need to represent arbitrary a composition made of different flowers of different sizes.
Give this layer the next shown parameters:
This is what we’ve got on the final stage!
View full size
here.
