Canon 30D, handheld
Mamiya 80mm at f4
1/3200 second at ISO 250
Nothing up my sleeve
bluets Houstonia caerulea and spots

As much as this may look like digital trickery, there has been no editing done on this image at all – this is straight out of the camera (well, except for resizing) and would have appeared this way even on film. What you're seeing are solely optical effects from exploiting certain conditions.

The Mamiya 80mm macro lens that I'd adapted to use on Canon bodies has, like most macro lenses, the ability for very short depth of field and smooth defocused areas. By getting very close to the diminutive bluet flowers (Houstonia caerulea) and shooting with the maximum aperture of f4, I could pick specific blossoms to be sharp, while others only a short distance further away would go out of focus quickly. But the key part was doing this at an angle that captured the river in the background, and specifically the sunlight twinkling on the rough water. Each sharp reflection of the sunlight was significantly out of focus, rendered into a vague circle by being very bright against the darker water, yet still blocked in places by both the sharp flowers and the blurred blossoms and grasses of the shore. That's it – nothing fancy. A little luck helped put a cluster of bright spots right behind the flower that served as my point of focus.