Outside
Something that has been helping me immensely of late is making sure I'm getting outside. If not every day then every couple of days at least. I took up bird-watching at the beginning of the year. I grab my binoculars, head out to the park, and get back into nature.
There's something really mindful about being in nature, and, for me, about bird-watching in particular. When I'm doing that, it's hard for me to be in rumination mode. When the air is full of whistles and cries, the wind is blowing (or pointedly not blowing), the trees are tree-ing as hard as they can, the river is flowing, I'm all of a sudden in the moment, that moment of nature and growth and now-ness.
I can't recommend it highly enough. Get outside when you can. Get into nature if you can. There's something reassuring about recognizing that the world is there despite everything that is happening inside our heads. The birds sing. The Sun rises, so to speak. The leaves grow and fall and grow again. And we grow and fall and grow again with them. We rise with the Sun and we sing with the birds.