>>32983306uhhh, there should be infographics kicking around elsewhere, but the short version is:
breed magikarp and ditto. continue doing this, while saving periodically (usually every box or so). once a shiny is encountered, reset to previous save. replace magikarp in daycare with target pokemon*, continue to breed, and the shiny should appear in the same place (e.g. 10th egg for both), but as a different species.
*this isn't 100% easy. gender ratios can affect it, and things like everstones need to be taken into account.
basically, you get to take a look at the shiny before you breed it, in a sense, as well as finding the shiny quicker (since magikarp has the lowest egg-hatching-steps). I'm personally using it to see how the gender roll turns out, so I can get certain pokemon as certain genders (specifically, Nidoran, since I want a nidoking, not a nidoqueen)