Its main sources are orders and Yunxiufang. Personally, I think the most cost-effective in the early stage is the Tibetan incense that can be synthesized from level 14 to level 15.
Then no matter what kind of product it is, try to complete the order first, and then sell it to Yunxiufang.
The price of the former is about 1.3 to 1.6 times higher than that of the latter, and it also has popularity and some items.
Basically, you can earn gold coins as long as you place an order. However, apart from the natural refresh of orders, you also need to use order deeds. There are not so many usable items, so in the end, the most important gold coin output is Yunxiufang, also because it consumes more. , in the middle and later stages, its output will be largely relied on to support many areas in the game that need to be cultivated.