Oooh good question! Within the Genshin fandom I think Wrioney is my biggest comfort ship, especially to write. But Ittorou also has a special place in my heart as one of my first ships, & I have a couple Chiscara fics I reread over and over when I'm sad!
As for tropes...maybe roommate AUs? That's very similar to how my BF & I got together so I really enjoy them haha 💖