Self-care is extremely important. But defining what self-care is and what it means can be different from person to person.
I'm an extremely anxious person. I have been my whole life. I like to fill my schedule, spread myself thin and please as many people as possible. This mindset was not stable or sustainable... and I learned that quickly. I've learned a lot about mindfulness and self-care through professional counseling. The most important thing I learned is self-care doesn't need to be this big production, but it does need to happen at least once a day. My versions of self-care include taking 2 minutes to do deep breathing, listening to good music really loud, cleaning my room or spending time with a friend. I hope to encourage my students to look inward and reflect on how they're feeling. Below is a graphic with little things that can greatly reduce stress and improve one's mood.
Something that I think would be helpful for my students during class is giving them little "brain breaks" where we can get up, walk around, go outside, or give them a few minutes each class period to catch up on organization or whatever they may have. A task that may be fun is to measure heart rates before and after using various breathing techniques that I have learned and are proven to reduce your heart rate. That way, the students are learning about their bodies in a scientific sense but also on a personal level. I want to be sure that there is open communication and trust between my students and me so if life happens and an extra day is needed on an assignment, that the student feels comfortable and supported by letting me know.