I love square breathing and 5-4-3-2-1 grounding for when I'm having anxiety or need to center myself quick and/or out in public.
https://www.healthline.com/health/bo...ld-your-breath
https://www.urmc.rochester.edu/behav...r-anxiety.aspx
I'm not someone that can easily meditate so my therapist suggested bilateral stimulation music which has been great for me to relax every night. You can find playlists on spotify and youtube by searching EMDR music or bilateral stimulation music.