Old videogames I've played before, or books and comics I've read a bunch of times. Some favourites include Final Fantasy 7,8 and 10, Baldur's Gate, Master of Orion 2, Howl's Moving Castle (the book), Azumanga Daioh. One time, when I was ill, I read 100 chapters of Naruto in a day and hit the cap on the Shounen Jump app 
the 90s BBC TV adaptation of Pride and Prejudice. It's very easy and calming to watch.
Looking at pictures and videos of Guinea Pigs.
A nice cup of tea. In the morning, I drink standard black tea with soy milk (I may be allergic to cow's milk, but I am still a Northern English lady, dammit and I must have my tea!) and in the afternoon, I like either licorice and peppermint tea, or chamomile.
Donburi and fried rice are my comfort foods of choice.
When I'm super overstimulated, I often put on a rain noise playlist on Spotify, it really helps.
I like to paint minis. It's really soothing, and if I'm feeling upset, painting something really familiar, like Space Marines while putting on Warhammer lore videos on youtube (Snipe & Wib's Codex Compliant series being my fave) is very calming for me, because I've been collecting and painting since I was eleven or so.
Kind of odd to be comforted by painting gigantic religious fanatic super-soldiers with chainsaw-swords who serve an evil empire but... I just think they're neat! And it's so pleasing to add towards an army that all matches and then you can play with them.
