i have a lens reversing adapter so i screw the front of the lens onto the adapter (52mm), then basically, mount the lens onto the camera backwards (front of lens into camera). Obviously, you lose control of AF and aperture, and you have an incredibly small DOF less than 1mm at 35mm end, also when you are literally 1-2cm away from your subject, the flash is useless too so you need good light on the subject. It is more of a challenge than taking normal photographs, but when you get the right results, it's well worth it.
Also, the wider the lens you use, the more magnification you can get, so those of the stamen above were i think taken at 35mm, the one of the lily was at about 50mm, and if i used 18mm i could have got much closer, but losing even more DOF