There are two key ways to get them when it comes to getting Pokémon. Find them in the wilderness or by breeding.
You will find a simple Easy Breeding Guide, an advanced breeding guide and a competitive breeding guide here for more information about breeding in general.
The overall probability of having both wild and breeding a shiny Pokémon is 1/4096. Shiny breeding is very straightforward and we can improve our chances significantly with the use of two Pokémon of different languages. This is referred to as the Masuda Process.
Masuda Method Sword and Shield
This approach has been around for a while now and is named after Junichi Masuda, the Pokémon game maker.
The principal idea is to increase the brilliant opportunity by breeding two Pokémon in two different languages. You will see a traded Pokémon language in the top right next to the name of Pokémon except in your own language. The Masuda method raises your odds of getting shiny from 1/4096 to 1/683. Read the answer to How to Tell If a Pokemon Is Shiny?
A foreign Ditto is the best and most common strategy. Even if it operates for some international Pokémon, Ditto doesn’t contain you to a certain group of eggs. As long as you only breed for shiny Pokémon, it’s probably the most difficult part to get the international Ditto. Once you have one, place your shiny Pokémon in the daycare on the Route 5 or in the wild area and keep your eggs hatching until you are shiny. Quick reminding you that a Pokémon with a flame body in your team doubles your hatching pace, more can be found in my Easy Breeding Guide on breeding and hatching speed.
But with the Shiny Charm, you can improve your shiny chances a little more. After finishing your Pokédex in the left hotel in Circhester. Go up the lift and on the far left to the bed. Speak to the man in the back of the room and the shiny charm he’ll give you. Shiny charm enhances the total shiny opportunity for breeding by the Masuda method to 1/1365 and 1/512.