>>3419284My main sourse is Twitter. I follow a lot of artists, and whenever something new and good pops up, I get it through their retweets (and their new arts too). If you are interested, following creayus and people who draw CG from the list of her followings would work well.
I'm Russian, and my sources for some old arts I haven't seen anywhere else are Russian too.
I use albums of CG-themed groups in social network VK (I would have linked, but 4ch bans links, so try yourself, just google something like VK code geass and open links, it has photoalbums or фoтoaльбoмы category in each group, and you don't have to have an acc to look at it) and russian imageboard threads (which can exist for YEARS with almost no replies, but that saves some old arts).