Shiny Pokémon is the rarest type of creature you can catch on Pokémon Sun and Moon. These Pokémon in particular will require your persistence because you might have to repeat the process all over again. Thus, here's a guide on how to easily farm for Shiny Pokémon.
Pokémon Sun and Moon - Get Adrenaline Orb And False Swipe
To get you started, you need Adrenaline Orbs which you can unlock when completing the Mallows Trial and upon reaching the second island. Adrenaline Orbs can be purchased from the Pokémon Center right at the bottom of the items list. Take note that Adrenaline Orbs are new to this game and they are basically used for Pokémon you meet along the way to call for help during battles. You can only use one Adrenaline Orb in each battle and it lasts for its entire duration.
Next, you will need a Pokémon that has False Swipe move which can be earned at TM 44. If you don't have it, remember that gift Pokémon Munchlax is the way to go. This is very much essential in this battle because once you attack a Pokémon you will inflict its HP to 1 instead of totally killing it.
Pokémon Sun and Moon - How To Easily Farm Shiny Pokémon
If you want a particular Shiny Pokémon, you have to make a random encounter with them along the way. However, right at Melemele Island, you can actually get a Shiny Pokémon. Begin the battle by using False Swipe to bring down the enemy Pokémon's health to 1 HP. However, the level of your Pokémon matters but in bringing down the enemy's HP, the important thing here is to inflict below 50 percent. This is the minimum requirement to activate the SOS mechanic. At this moment, use the Adrenaline Orb for your enemy Pokémon to call for help.
Pokémon Sun and Moon - Which Pokémon Usually Shows Up?
The Pokémon that will show up to assist the struggling creature is based on three criteria. First, it has better individual values (IVs). Second, it has a hidden ability. Third, it is Shiny. Once the rescuing Shiny Pokémon shows up, kill the old Pokémon. However, there are instances that the rescuing Pokémon is of the same type so you have to repeat the same process until you get the Shiny Pokémon you've been hunting for.