Masuda method!!! Masuda method!!! Can't recommend this enough!!!
It gives you a STRONG shiny if you do it right!! (And faster :00)
(I havent played pkmn in a while so I might describe somethings weirdly lmAO but I was a shiny hunting master and remember a thing or two!!)
I recommend getting a 6IV Japanese Ditto (Item: Yarn) breeding with another pokemon from your game (or others pokemon, as long as it's in your area) (only get 6IV if you want a strong shiny)
Breeding a foreign (Japanese recommended) pokemon with a pokemon that's in your area, gives you a higher chance of getting a shiny!
Having one (1) pokemon in your party with the ability flame body, it makes the eggs hatch faster!!
go into the gate thing at the farm right in front of the nursery, activate your tauros, and dash around in it until the lady in front changes her pose, get egg, go back to gate do same thing until egg hatches (I recommend picking up some eggs on the way if the pokemon breeds that fast! But you do you :) )
If there's a nature in specific you want for your shiny, give the pokemon (Not ditto) an everstone, it 100% carries on the nature.