If held, increases the chance of an egg from this Pokémon being Shiny.
Gold Incense can be bought in the Item Store of the Pokemon Center for either 20 Daily Coins (per Gold Incense), or 10 Gold Incense for 1 Snd Coin. You can give it to a Pokemon in-game and use it for breeding afterwards in the Pokemon Center.
Having a Pokemon hold a Gold Incense whilst breeding will increase the chance of the child being shiny by 4%. It is possible to have both parents hold a Gold Incense, allowing for an 8% chance from two Gold Incense.
Gold Incense is a one-time use item; if used during breeding, it will be consumed after the breeding.