Masuda Method breeding is the most reliable way to get a Shiny. To perform this, the 2 Pokemon you are breeding need to be from different languages. You will see this on their Summary page, with an abbreviation corresponding to the language they originate in (FRE = French, JPN = Japanese, etc). This drastically increases the chances that the offspring will be Shiny.
I know your pain, though. Just keeping the 4+ IV Bulbasaurs I was breeding, I had about 7 boxes full. Finally got one. Now, I'm experiencing a similar phenomina with 5 IV Stealth Rock/Whirlwind/Drill Peck Skarmorys.
If you are really, really, REALLY in need of a shortcut, you can use the Shiny Value Exchange subreddit, however I believe it requires access to a hacking device of some kind to actually identify the Shiny Values. I'm not super clear on that part. Basically, every Trainer and every Egg has a 4 digit code assigned to it. If they match, the Egg will hatch Shiny. Knowing your own Shiny Value, you can work with others to obtain Eggs that match your Shiny Value.
https://www.reddit.com/r/SVExchange
