My current macro setup.
The winner of my macro performance test, a reversely mounted Zeiss 58/2
taped on a M42 extension tube with an M42-Nikon adapter 49>52mm step-up and reverse-adapter. Despite its age, this lens
really produces quality images with a beautiful bokeh and still
performes well if stopped down to F11-F16. (Read some interesting
details about this lens with a quality compoarison to a Nikkor lens
from 2006 here).
The focus lies currently on the box on the right, approximately 85mm in front of the lens. Focus of the lens is at minimum, this doesn't make much difference for the distance, but moves the backlens in the hull and thus creates a lens-hood.
The 12mm extension ring, formerly used as part of a cable connection for a reversely mounted lens, now contains a Dandelion chip. It allows for auto-exposure and -
more important - TTL-flash. This also gives me full control over my
external flash with limited manual options.
With a 12mm tube this setup results in a 1:1.2 macro lens (29mm on a 23.9mm chip). With additional 20mm tubes it is 1.14:1 (21mm) and with the additional third 36mm tube 1.7:1 (14mm).
But more handy than an external flash is the milkbox flash diffuser which guides the light of the oncamera flash to where it is required. The front diffuser can be folded and put into the rearmost part. The right piece, currently beside the camera, is used as a telescope and contains a 3W cree LED which can be used during focussing (didn't use it lately). For transportation, the whole diffuser is not much larger than what's over the lens.
Accidentially also on this picture is the mod of my Phottix battery grip: Instead of connecting the strap to the tripod thread, I installed a loop. This way the body is smaller and even.
See the comments for example shots, thanks for looking!