Another thing you can do, without being creepy about it, is start noticing the posture of the people around you. When you’re standing in line at the grocery store, what’s happening in the shoulders and hips of the guy standing in front of you? Posterior or anterior pelvic tilt? Lordosis? Kyphosis? Transverse rotation? Shoulders level, rotated, dropped, etc.
We get good at body-reading by reading lots of bodies. When you don’t have client bodies to learn on, you can still learn a ton by people-watching.