How do you practice self-care during your workday?

I'm in my 4th year of teaching and have some angst about returning to school tomorrow. I need some advice on how to make my day flow smoother with self-care practices. I know some co-workers who:

• lock their classroom door on prep
• play music throughout the day
• go for a walk during their lunch break

What are some self care practices you have to get you through the day?