MOVEMENT.
When lifting weights for upper body, be sure to start with shoulder blades pulled back towards your spine.
Maintain this position during the entire movement/exercise.
This places your head and shoulder complex in a "home base" and neutral position, thus allowing for optimal posture, activation and protection for your body.
Everyday life application: squeeze your shoulder blades together 5 times, 5 times per day to check in with your posture and relieve stress in your neck, mid back and low back.