This is an alternative to the
FMMB and it is also wireless! No ETTL cord
(CANON OC-E3 OFF CAMERA SHOE CORD ) needed!
If you really like the
FMMB (Front Mounted Macro Bracket) but don't know how to DIY one for yourself, fret not. There's an easy way out, and it won't really cost you a lot! Items like extension tubes and
Canon Speedlite 270EX II Flash
are items that will come in really handy in macro anyway!
Chances are, you might already have most of the items already, and all you need is one simple bracket. (HDE flash bracket shown below, or something similar) so you can bring the 270EX II even closer to the front (if you have to), and closer to your macro subject.

I used my 40D body, MP-E65 lens and 1.4x teleconverter here just for illustration. This wireless macro rig works only with IF (internal focus) lenses like the
Canon EF 100mm f/2.8L IS USM
or
Canon EF 100mm f/2.8 Macro USM
, or
Nikon 105mm f/2.8G ED-IF AF-S VR 
, and with extension tubes (prefered over teleconverter), and of course, newer bodies like
Canon EOS 60D 
,
Canon EOS 7D
,
Canon EOS Rebel T3i /600D
Some side notes:
- the 270 EX II should be
upside down/belly up.
- Only the newer Canon body like 60D, 7D, and 600D can trigger the 270EX II wirelessly.
- Mount Ring/tripod collar B is for the older Canon 100mm (USM) while D is for the newer Canon 100mm L (IS)
- You won't be able to rotate the mount ring all the way up (flat surface on top) unless you have at least one tube attached to the body, as the mount ring will hit the popup flash.
Why you need at least one extension tube if you want to use the tripod collar/mount ring: