Getting shiny Pokemon are easy!
You say you want a Pichu? Well, I'll tell you, the Masuda Method is the thing you want!
The Masuda Method is simple - when you breed two Pokemon from different countries, the chance of getting a shiny Pokemon increases five times! About a 1/1638 (as opposed to the normal 1/8192) :D
A good way to do this is to look for a Ditto on the GTS from another country - when you find one, breed your Ditto with any Pokemon (that isn't on this list) and there is an increased chance of finding a shiny! It's still a 1/1,000 chance of getting one, but at least it's better than 1/8000. xD
Hope I helped. :)
Source: Experience and Bulbapedia Masuda Method page