not pokeradar not masuada method not X&Y and not shiny charm (i am playing Pokemon white1)
Without using any of those, it is very hard to get a shiny. Try going on GTS negotiation some time. There are many people who are willing to trade weak shiny versions of common Pokemon for strong, rare, non-shiny ones.
Not using any of those methods your best bet would be to either look for lots of them in the wild or breed that Pokemon and hatch the eggs with a Pokemon that has an ability such as Flame Body or Magma armor in your team while you run around. Even so it may still take ages to get a shiny not using the Masuda method considering the 1/8192 chance of finding a shiny while breeding or in wild.