>>14400793Danbooru, pixiv, twitter; maybe nijie and seiga.nicovideo if you are feeling like really deep diving. But those latter sites you'll have to know jap to browse
Danbooru is a nobrainer, just type in the Touhou tag and you will find everything ever posted unless it is a banned tag in which case you need a builder or premium account or just go to gelbooru where everything from dan gets scraped from.
Finding Touhou on pixiv is easy, just look an any touhou pic and they can recommend you similar pics endlessly like youtube sidebars
twitter is harder. You can find a ton of twitter artists over the danbooru wiki. But even that has a ton of gaps. You can also follow a dozen of them, and see what they retweet, and they retweet other artists too through which you can discover new ones, but you are going to need to regularly check on twitter to keep up with the artists that post there since there is no tagging going on.
Nijie and seiga.nicovideo are, just like I said, pixiv but with no english support.
