Shiny Staraptor=awesome

I was so determined to get a shiny eevee that I bred them for two days straight. One finally hatched on December 26, and I named her Faith. But as it turns out, her IVs were awful, and then I discovered my favorite Umbreon moveset that requires eggmoves she didn't have. D: It wasn't a total waste though--two of the eevee babies had almost perfect IVs for Jolteon/Espeon, so I got my two best battling eevolutions from that insane amount of breeding. ^_^
The only two shinies I've randomly encountered have been Tentacool (leaf green) and Cherubi (diamond). The rest I've either chained or gotten through trading (except for the eevee that I bred--but that's all luck, too).
You can increase your chances of finding a shiny by using the pokeradar. That's what I mean by chaining. You need a ton of repels and it's easiest to do with a swarm.
What you do is:
Find a big patch of grass
Use repel
Use the radar
Once you encounter a pokemon you want to chain, either defeat it or catch it.
The radar will go off again as soon as you leave battle.
This is where it gets tricky. Up to 4 patches will shake again.
One patch will be right next to you. One will be 2 steps away, one 3 steps away, and the last will be 4 steps away.
You want the one that's four steps away. That one has the best chance of having the same pokemon you just defeated.
The chart below would be an example--the O is you, the x's are the range of the radar, and the 8's are the ones that shook. You'd want the bold 8.
x x x x
8 x x x x
x x x x x x x x x
x x x x 8 x x x x
x x x x x 8 x x x
x 8 x x O x x x x
x x x x x x x x x
x x x x x x x x x
x x x x x x x x x
x x x x x x x x x
Your chance of finding a shiny will increase the higher up you get in this 'chain.' Once you get to 40, you have a pretty good chance (5% or something like that), but it's easier said than done since you're more likely to break the chain the higher you go. I've never made it to 40, so I usually start to 'reset' at 20-30 and hope for the best. To reset, you recharge the radar and use it again rather than go into any more battles, until you see the shiny patch (it sparkles instead of shakes--then you know there's a shiny pokemon there). Trust me, you'll know the patch when you see it!
I've gotten 3 shiny bunearies, a shiny corsola, and 4 shiny skitties doing this. I don't have the extras anymore, sorry! I've traded them all away... The corsola was completely on accident--I was showing a friend how to chain and the patch showed up wicked early in the chain.
This is DPP--I don't think there's a pokeradar in HG SS?