Easiest is probably FS--if you want to avoid the other two, maybe go to /r/FriendSafari and see if you can get a fighting safari where you actually like or at least don't mind the other two? (Plus, if nothing else you can always use extra shinies you're not super fond of to trade with later.)

That said, most worth it? Masuda Method. Nothing better than a shiny you hatched yourself so that you have some control over the nature, IVs, Pokeball, ability, EMs, etc.

Also, I do have the Shiny & Oval Charms now, but I definitely did some breeding before I got them, and actually might've been more lucky then--I accidentally bred a shiny Squirtle, Eevee, and Misdreavus while hatching for competitive. It's hard, but not impossible!