In Black and White, most shinies just appear randomly. Go walk in grass and see lots of Pokemon, and eventually some of them will be shiny!
And yes, you can use a Japanese Ditto to get shinies. If you put the Pokemon you want a shiny of in daycare with a Japanese Ditto, your chances of getting a shiny are much, much better. You still have to hatch lots of eggs, but you'll get a shiny faster.
And yes, you can use a Japanese Ditto to get shinies. If you put the Pokemon you want a shiny of in daycare with a Japanese Ditto, your chances of getting a shiny are much, much better. You still have to hatch lots of eggs, but you'll get a shiny faster.