Hunting Shiny pokemon are difficult, for there is a 1/8192 chance you'll encounter one, and even that is not guaranteed. Using the Masuda Method and obtaining the Shiny Charm and Round Charm may increase these chances dramatically, so you may be able to actually find one that is not realted to the main story line!
Everyone knows about the Masuda Method! It is a method determined by a nintendo employee! It where you take a pokemon from your game (preferably the pokemon you want to be shiny), and Trade pkkemon for a Ditto from another country. This will increase the chance of a Shiny pokemon being inside an egg (Daycare Located on Route 3) to 1/2193, if i remmember correctly!
After completing a certain version of the pokedex, go to the preffessor and she will give you a charm or two, these being the Shiny charm or the round charm or bothe.
Increases chances pf seeing a wild shiny.
Increases egg production rate at Day Care.
If you are hunting Shiny pokemon you want to not loose it. So, make sure you have mant pokeballs and an array of different pokemon at different levels so your equipped perfectly for all levels of Shiny!!!
Remeber, you can also find a shiny in the Rustling Grass. If you recall, Bianca tells you that the rustling grass brings a surprise!