1) dailyjuhaku: Even though I don't really use tumblr anymore, I still appreciate the juhaku community is still going strong!! I think it's very wholesome, especially since Magi isn't very big now that the manga has ended.
2) getyourwordsout: It's only my first year participating, but I'm finding that the community is incredibly inspiring and resourceful already :D There are a lot of great people running it and participating in it, and I'm really hopeful that it'll help me be a more consistent writer (rather than just a few bursts during the year and FRANTICALLY SCRAMBLING DURING NANOWRIMO).
3) unNocturnal: One of my favorite artists to commission, I love how dreamy their sketches and line work always look *w* Their patreon has some very reasonable offerings, especially for their skill level. I'm also currently using art of theirs as my phone lock screen, and it always brings me a smile :D