Its known as the mind-muscle connection. What helped me was visualization, slow eccentrics have helped me with some body parts (also, instead of dropping to the

Its known as the mind-muscle connection. What helped me was visualization, slow eccentrics have helped me with some body parts (also, instead of dropping to the bottom of a movement, like a push-up, try to pull yourself down; if you're squatting, pull yourself down using your erectors instead of just dropping, etc...), and a lot of time. I'm still not there with some body parts / movements, but I have muscle development on those areas, regardless.