sigh The chances of finding/encountering any shiny Pokemon will always be 1/8192 with the exception of the Masuda method.
The Masuda method is a method where you breed two Pokemon from different countries (like a Poliwag from America, and a Poliwag from Germany) and the egg it produces will have a much greater chance (1/ 1/2048*) but it comes with the nuisance of hatching each and every one of those eggs.
*In Pokemon Black and White, this chance was lowered even further to 1/1366.
There is no easier way to obtain legitimate shiny Pokemon without the Masuda method.