Lie on your back and let the belly go completely soft — stop sucking it in. Most of us spend the whole day with the gut braced and tucked; it's the body's central area for feelings and emotions.
Knees up, point the hips toward the sky and un-clench. You sit on these all day — the butt cheeks are a common place people squeeze and tuck without noticing.
Sit crisscross-applesauce and raise both arms to 45° like a star. Picture a vent in each armpit and let that thing breathe.
Open the front of the neck and breathe deep. Anxiety tucks the throat in — the tell is that 'gulping' feeling. Rotate the head side to side and let it release.