I'm not a fan of the "nun's hood" style of diffusers. First, in many situations the surrounding tree trunk, twigs, brush, etc. interferes with getting a desired angle, or even getting close enough. Second, the light is relatively uniform, which, in many cases, is convenient, but not always the most interesting, and totally prevents creating any strong side or back light. But for many, it's a simple and practical solution.
Photos below show the type of flash+ diffuser I use, which is usually attached to a bracket with some type of magic arm and/or ball head so that I can position the light wherever I wish, and for what I think is best for each subject. I believe this makes for a more three-dimensional illumination style, with subtle shadows not possible with the big hood diffusers. This is the type of system macro photographers used for years until the hood-style became available a few years ago.
As for a twin-flash setup, the example shown by the OP looks terribly cumbersome, and doesn't look practical for anything except low magnification shots of flowers. Modern twin flash setups are much more compact than shown in that example, and in fact, allow attaching even more than two flash heads. The position of each head can be placed anywhere around the ring. Importantly, the power of each head can be controlled independently, so some "shape" can be provided to the light with the results being not too flat and uniform. For sure, the flash heads should have a diffuser to increase the size of the head (see photo below).
Lester Lefkowitz, author of
The Manual of Close-Up and Macro Photography, Volumes I & II
www.MacroPhotographer.net
Diffuser is made from foamcore assembled with a hot glue gun. Diffuser face is a kitchen paper towel. I have since shortened the wood handle to get the diffuser closer to the lens.
Variation using a magic arm
Another variation
Here's what it looks like in the field. Arrow points to subject; results shown in next photo below.
Photographed with the rig directly above.
Another subject using the same flash rig.
My twin-flash setup . Diffuse on left is homemade, right is commercial. This rig made photo below.
Leaf-cutter ants made using twin-flash, above.
This is a technique I use a lot; allows me to position the flash anywhere I like. Holding the camera in one hand is okay, since the flash freezes any motion. Being a photographer, I was fortunate to have been born with five arms.
Conventional shot of a mushroom with diffused flash ON the camera.
Holding the flash off camera, above and slightly behind the mushroom.
