shiny Pokemon are rare Pokemon with a different colour there is a 1-80% chance that you will find one so there is no easy way to find one unless you cheat!>:)
The easiest way would be to RNG abuse, but this is in the wrong category.
The same way you would catch a normal Pokemon. The only difference is is that the Pokemon is shiny.
Shiny pokemon are found in random throughout the game. There is no solid way to get one.
Either cheat or "chain" 40 pokemon.
you go to a Pokemon Rocks USA
The easiest way is to use the Poke'Radar.
The easiest way to level up is to feed Pokemon Rare candies.
have EMERALD en clone a Pokemon with that rare candy
there is no easy way im not exactly sure of the figures but there is an extremely low chance of catching a shiny pokemon, so just keep on hunting for it
Probably trade with Ruby.
The easiest way is to buy a Gameshark, there are cheats pre-set into it.
You just become awesome by being awesome then you be awesome and get it.