“Just focus on your breath,” or… maybe do something else, that might work, too.
When you have a trauma background, sitting quietly with your eyes closed and focusing on your breath can be terrifying rather than calming.
Don’t blame yourself if this is you. It’s not your fault that your ears and brain are scanning frantically for the sound of footsteps. That your brain is making its to-do lists and chiding you for sitting and not to-doing. That your abdomen muscles shudder and scare you when you try to breathe deeply into your belly. Deep breathing deepens your feelings. If you’re already scared or nervous, you can try to force your way through it with box breathing, and if this works for you, awesome. For me, I usually don’t have the patience to get to the point where I’m “calm” again, and I’ve spent many years trying to get there this way.
In case it’s helpful for anyone, this is where I find calm:
Staring at a flame
Listening to wind chimes
Staring at water (in a creek, in my cup, as rain, as steam, as droplets falling from an icicle, whatever) and thinking about the water cycle and how all water is and always has been one, and this water in my cup used to be ocean and cloud
Immersing myself in intense heat, whether it’s a hot shower or just stepping out into the summer
Watching birds and trying to figure out what’s going on with them
Tending my plants, but only if I’m not on a schedule and am genuinely just puttering
Looking at my tidy freezer and pantry (note:, this is rare, my freezer and pantry are a mess right now and that is NOT calm), and feeling like I’ve done what I can and I’m ready for whatever
Your calm may vary, and it probably has to do with where your natal moon is – mine is in Taurus, and these things that I’ve listed are pretty normal Taurus calm-things –- but it can also be clouded by past events/other astrological influences.